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Solucionario Matematicas 3

1. The document provides solutions to 10 differential equations by finding the general solution y in terms of the constants c1, c2, etc. and the exponential terms involving the roots m1, m2, etc. 2. Each solution is of the form y = c1e^m1x + c2e^m2x + ... where the roots m1, m2, etc. are found by factorizing the characteristic polynomial of the differential equation. 3. The solutions involve exponential, exponential-polynomial, and polynomial-exponential terms depending on the differential equation.

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0% found this document useful (0 votes)
140 views68 pages

Solucionario Matematicas 3

1. The document provides solutions to 10 differential equations by finding the general solution y in terms of the constants c1, c2, etc. and the exponential terms involving the roots m1, m2, etc. 2. Each solution is of the form y = c1e^m1x + c2e^m2x + ... where the roots m1, m2, etc. are found by factorizing the characteristic polynomial of the differential equation. 3. The solutions involve exponential, exponential-polynomial, and polynomial-exponential terms depending on the differential equation.

Uploaded by

Marcoebi
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
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Ejercicio 3.

1
Hallar la solución general de las siguientes ecuaciones

1) (𝐷2 + 9𝐷 + 18) 𝑦 = 0
𝑚2 + 9𝑚 + 18 = 0
(𝑚 + 6)(𝑚 + 3) = 0
(𝑚1 + 6)(𝑚2 + 3) = 0
𝑚1 + 6 = 0 𝑚2 + 3 = 0
M1= -6 m2=-3

𝑦 = 𝑐 𝑒 𝑚1 𝑥 + 𝑐 𝑒 𝑚2 𝑥
1 2

𝑦 = 𝑐1𝑒 −6𝑥 + 𝑐2𝑒−3𝑥

2) (𝐷2 − 3𝐷 − 10) 𝑦 = 0
𝑚2 − 3𝑚 − 10 = 0
(𝑚 + 2)(𝑚 − 5) = 0
(𝑚1 + 2)(𝑚2 − 5) = 0
𝑚1 + 2 = 0 𝑚2 − 5 = 0
𝑚1 = −2 𝑚2 = 5

𝑦 = 𝑐1𝑒−2𝑥 + 𝑐2𝑒5𝑥

3) (𝐷2 + 4𝐷 − 21) = 0
𝑚2 + 4𝑚 − 21 = 0
(𝑚 + 7)(𝑚 − 3) = 0
(𝑚1 + 7)(𝑚2 − 3) = 0
𝑚1 + 7 = 0 𝑚2 − 3 = 0
𝑚1 = −7 𝑚2 = 3

𝑦 = 𝑐1𝑒−7𝑥 + 𝑐2𝑒3𝑥
4) 𝐷2𝑦 = 𝐷𝑦
𝐷2𝑦 − 𝐷𝑦 = 0
(𝐷2 − 𝐷)𝑦 = 0
𝑚2 − 𝑚 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −1
𝑐=0

𝑚 = −(−1) ± √(−1)2 − 4(1)(0)


2(1)
𝑚 = 1 ± √1
2
𝑚 = 1±1
2

1−1 1+1
𝑚1 = 𝑚2 = 2
2
M1= 0 m2=1

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑒1𝑥
𝑦 = 𝑐1𝑒0 + 𝑐2𝑒𝑥
𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑒𝑥

𝑦 = 𝑐1 + 𝑐2𝑒𝑥
5) (𝐷3 − 7𝐷 + 6) = 0
𝑚3 − 7𝑚 + 6 = 0
𝐷6 = ±1, ±2, ±3, ±6

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 0 −7 6 𝑚 = 1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
1 1 −6 𝑚−1=0
1 1 −6 0

(𝑚2 + 𝑚 − 6)(𝑚 − 1) = 0
(𝑚 + 3)(𝑚 − 2)(𝑚 − 1) = 0
(𝑚1 − 1)(𝑚2 − 2)(𝑚3 + 3) = 0

𝑚1 − 1 = 0 𝑚2 − 2 = 0 𝑚3 + 3 = 0
M1=1 m2=2 m3= -3

𝑦 = 𝑐1𝑒1𝑥 + 𝑐2𝑒2𝑥 + 𝑐3𝑒−3𝑥

𝑦 = 𝑐1𝑒𝑥 + 𝑐2𝑒2𝑥 + 𝑐3𝑒−3𝑥


6) (𝐷4 − 𝐷3 − 7𝐷2 + 3𝐷) = 0

𝑚4 − 𝑚3 − 7𝑚2 + 3𝑚 = 0
(𝑚3 − 𝑚2 − 7𝑚 + 3) = 0
𝐷3 = ±1, ±3

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −1 −7 3 𝑚 = 3 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
3 6 −1 𝑚−3=0
1 2 −1 0
(𝑚 − 3)(𝑚2 + 2𝑚 − 1) = 0
𝑚1(𝑚2 − 3)(𝑚2 + 2𝑚 − 1) = 0

−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2
𝑎=1
𝑏=2
𝑐=−1
−(2) ± √(2)2 − 4(1)(−1)
𝑚=
2(1)

−2 ± √8
𝑚=
2
−2 ± √4(2)
𝑚=
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
−2 ± √4 ∙ √2
𝑚=
2
−2 ± 2√2
𝑚=
2
𝑚 = −1 ± 2√2

𝑚2 − 3 = 0

𝑚1 = 0 𝑚2 − 3 = 0 𝑚3 = −1 + √2 𝑚4 = −1 − √2

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑒3𝑥 + 𝑐3(−1+√2) + 𝑐4𝑒𝑥(−1−√2)

𝑦 = 𝑐1𝑒0 + 𝑐2𝑒3𝑥 + 𝑐3𝑒−𝑥+√2𝑥 + 𝑐4𝑒−𝑥−√2𝑥

𝑎0 = 1

𝑦 = 𝑐1(1) + 𝑐2𝑒3𝑥 + 𝑐3𝑒−𝑥+√2𝑥 + 𝑐4𝑒−𝑥−√2𝑥

𝑒𝑎+𝑏 = 𝑒𝑎 ∙ 𝑒𝑏

𝑦 = 𝑐1 + 𝑐2𝑒3𝑥 + 𝑐3𝑒−𝑥 ∙ 𝑒√2𝑥 + 𝑐4𝑒−𝑥 ∙ 𝑒−√2𝑥


𝑦 = 𝑐1 + 𝑐2𝑒3𝑥 + 𝑒−(𝑐3𝑒√2𝑥 + 𝑐4𝑒−√2𝑥)
7) (𝐷3 − 𝐷2 − 𝐷 + 1) = 0
𝑚3 − 𝑚2 − 𝑚 + 1 = 0
𝐷1 = ±1

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −1 −1 1 𝑚 = 1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
1 0 −1 𝑚−1=0
1 0 −1 0

(𝑚 − 1)(𝑚2 + 0𝑚 − 1) =

0 (𝑚 − 1)(𝑚2 − 1) = 0
(𝑚 − 1)(𝑚 − 1)(𝑚 + 1) =

0 (𝑚 − 1)2(𝑚 + 1) = 0

𝑚1 − 1 = 0 𝑚2 − 1 = 0 𝑚3 + 1 = 0
𝑚1 = 1 𝑚2 = 1 𝑚3 = −1

𝑦 = 𝑐1𝑒𝑥 + 𝑐2𝑥𝑒𝑥 + 𝑐3𝑒−𝑥

𝑦 = (𝑐1 + 𝑐2𝑥) + 𝑐3𝑒−𝑥

8) (𝐷6 − 8𝐷4 + 16𝐷2) = 0


𝑚6 − 8𝑚4 + 16𝑚2 = 0
𝑚2(𝑚4 − 8𝑚2 + 16) = 0
𝑚2(𝑚2 − 4)2 = 0
2
𝑚2 (( − 2 )(𝑚 + 2)) = 0
𝑚3 − 2 = 0 𝑚4 − 2 = 0 𝑚5 + 2 = 0 𝑚6 + 2 = 0
𝑚1 = 0 𝑚2 = 0
𝑚3 = 2 𝑚4 = 2 𝑚5 = −2 𝑚6 = −2

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑥𝑒0𝑥 + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−2𝑥 + 𝑐6𝑥𝑒−2𝑥


𝑦 = 𝑐1𝑒0 + 𝑐2𝑥𝑒0 + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−2𝑥 + 𝑐6𝑥𝑒−2𝑥
𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑥(1) + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−2𝑥 + 𝑐6𝑥𝑒−2𝑥
𝑦 = 𝑐1 + 𝑐2𝑥 + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−2𝑥 + 𝑐6𝑥𝑒−2𝑥

𝑦 = 𝑐1 + 𝑐2𝑥 + (𝑐3 + 𝑐4𝑥)2𝑥 + (𝑐5 + 𝑐6𝑥)𝑒−2𝑥

9) (𝐷5 − 12𝐷3 + 16𝐷2) = 0


𝑚5 − 12𝑚3 + 16𝑚2 = 0
𝑚2(𝑚3 − 12𝑚 + 16) = 0
𝐷16 = ±1, ±2, ±4, ±8, ±16

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 0 − 12 16 𝑚 = 2 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
2 4 − 16 𝑚−2=0
1 2 −8 0
𝑚2(𝑚 − 2)(𝑚2 − 2𝑚 − 8) = 0
𝑚2(𝑚 − 2)(𝑚 − 2)(𝑚 + 4) = 0
𝑚2(𝑚 − 2)2(𝑚 + 4) = 0
𝑚3 − 2 = 0 𝑚4 − 2 = 0 𝑚5 + 4 = 0
𝑚1 = 0 𝑚2 = 0 𝑚3 = 2 𝑚4 = 2 𝑚5 = −4
𝑦 = 𝑐1𝑒 + 𝑐2𝑥𝑒 + 𝑐3𝑒 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−4𝑥
0𝑥 0𝑥 2𝑥

𝑦 = 𝑐1𝑒0 + 𝑐2𝑥𝑒0 + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−4𝑥


𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑥(1) + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−4𝑥
𝑦 = 𝑐1 + 𝑐2𝑥 + 𝑐3𝑒2𝑥 + 𝑐4𝑥𝑒2𝑥 + 𝑐5𝑒−4𝑥
𝑦 = 𝑐1 + 𝑐2𝑥 + (𝑐3 + 𝑐4𝑥)2𝑥 + 𝑐5𝑒−4𝑥

10) (𝐷2 − 6𝐷 + 9)3𝑦 = 0


(𝑚2 − 6𝑚 + 9)3 = 0
((𝑚 − 3)2)3 = 0
(𝑎𝑚)𝑛 = 𝑎𝑚𝑛
(𝑚 − 3)6 = 0

𝑚1 − 3 = 0 𝑚2 − 3 = 0 𝑚3 − 3 = 0 𝑚4 − 3 = 0 𝑚5 − 3 = 0 𝑚6 − 3 = 0
M1=3 m2-3=0 m3-3=0 m4-3=0 m5-3=0 m6-3=0
𝑦 = 𝑐1𝑒3𝑥 + 𝑐2𝑥𝑒3𝑥 + 𝑐3𝑥2𝑒3𝑥 + 𝑐4𝑥3𝑒3𝑥 + 𝑐5𝑥4𝑒3𝑥 + 𝑐6𝑥5𝑒3𝑥

𝑦 = (𝑐1 + 𝑐2𝑥 + 𝑐3𝑥2 + 𝑐4𝑥3 + 𝑐5𝑥4 + 𝑐6𝑥5)3𝑥

11) (𝐷3 − 4𝐷2 + 5𝐷) = 0


𝑚3 − 4𝑚2 + 5𝑚 = 0
(𝑚2 − 4𝑚 + 5) = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −4
𝑐=5

𝑚 = −(−4) ± √(−4)2 − 4(1)(5)


2(1)
𝑚 = 4 ± √−4
2

𝑚 = 4 ± √4(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
4 ± √4 ∙ √−1
𝑚=
2

𝑖 = √−1
4 ± 2𝑖
𝑚=
2
𝑚 =2±𝑖
M1= 0 M2=2-i M3=2-i

𝑦 = 𝑒[𝑐1𝑠𝑒𝑛𝑏𝑥 + 𝑐2𝑐𝑜𝑠𝑏𝑥]
𝑦 = 𝑐1𝑒0𝑥 + (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)2𝑥
𝑦 = 𝑐1𝑒0 + (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)2𝑥
𝑎0 = 1
𝑦 = 𝑐1(1) + (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)𝑒2𝑥
𝑦 = 𝑐1 + (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)2𝑥

12) (𝐷2 + 2𝐷 + 10)(𝐷2 − 2𝐷 + 2)𝑦 = 0


(𝑚2 + 2𝑚 + 10)(𝑚2 − 2𝑚 + 2)𝑦 = 0

𝑚2 + 2𝑚 + 10
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎1 = 1
𝑏1 = 2
𝑐1 = 10
−(2) ± √(2)2 − 4(1)(10)
𝑚=
2(1)

−2 ± √−36
𝑚=
2
−2 ± √36(−1)
𝑚=
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
−2 ± √36 ∙ √−1
𝑚=
2

𝑖 = √−1
−2 ± 6𝑖
𝑚=
2
𝑚 = −1 ± 3𝑖
M1=-1+3i m2=-1-3i

𝑚2 − 2𝑚 + 2
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎2 = 1
𝑏2 = −2
𝑐2 = 2

𝑚 = −(−2) ± √(−2)2 − 4(1)(2)


2(1)

𝑚 = 2 ± √−4
2
2 ± √4(−1)
𝑚=
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
2 ± √4 ∙ √−1
𝑚=
2

𝑖 = √−1
2 ± 2𝑖
𝑚=
2
𝑚 =1±𝑖
M3=1+i m4=1-i

𝑦 = (𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥)−𝑥 + (𝑐3𝑠𝑒𝑛𝑥 + 𝑐4𝑐𝑜𝑠𝑥)𝑒𝑥

13) (𝐷4 + 8𝐷2 + 16) = 0


𝑚4 + 8𝑚2 + 16 = 0
(𝑚2 + 4)2 = 0

−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=0
𝑐=4

𝑚 = −(0) ± √(0)2 − 4(1)(4)


2(1)
𝑚 = 0 ± √−16
2

𝑚 = 0 ± √16(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
0 ± √16 ∙ √−1
𝑚=
2
𝑖 = √−1
0 ± 4𝑖
𝑚=
2
𝑚 = 0 ± 2𝑖
M1=0+2i m2=0+2i m3=0-2i m4=0-2 i

𝑦 = (𝑐1 + 𝑐2𝑥)0𝑥𝑠𝑒𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)𝑒0𝑥𝑐𝑜𝑠2𝑥


𝑦 = (𝑐1 + 𝑐2𝑥)0𝑠𝑒𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)𝑒0𝑐𝑜𝑠2𝑥
𝑎0 = 1
𝑦 = (𝑐1 + 𝑐2𝑥)(1)𝑠𝑒𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)(1)𝑐𝑜𝑠2𝑥
𝑦 = (𝑐1 + 𝑐2𝑥)𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)𝑐𝑜𝑠2𝑥

14) (𝐷6 + 6𝐷4 + 9𝐷2) = 0


𝑚6 + 6𝑚4 + 9𝑚2 = 0
𝑚2(𝑚4 + 6𝑚2 + 9) = 0
𝑚2(𝑚2 + 3)2 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=0
𝑐=3

𝑚 = −(0) ± √(0)2 − 4(1)(3)


2(1)
𝑚 = 0 ± √−12
2

𝑚 = 0 ± √12(−1)
2

𝑚 = 0 ± √(4)(3)(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
0 ± √4 ∙ √3 ∙ √−1
𝑚=
2
𝑖 = √−1

𝑚 = 0 ± 2√3𝑖
2
𝑚 = 0 ± √3𝑖

M1= 0 m2=0 m3=0+√3𝑖 𝑚4 = 0 + √3𝑖 𝑚5 = 0 − √3𝑖 𝑚6 = 0 − √3𝑖

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑥𝑒0𝑥 + (𝑐3 + 𝑐4𝑥)0𝑥𝑠𝑒𝑛√3𝑥 + (𝑐5 + 𝑐6𝑥)𝑒0𝑥𝑐𝑜𝑠√3𝑥


𝑦 = 𝑐1𝑒0 + 𝑐2𝑥𝑒0 + (𝑐3 + 𝑐4𝑥)0𝑠𝑒𝑛√3𝑥 + (𝑐5 + 𝑐6𝑥)𝑒0𝑐𝑜𝑠√3𝑥
𝑎0 = 1

𝑦 = 𝑐1(1) + 𝑐2𝑥(1) + (𝑐3 + 𝑐4𝑥)(1)𝑠𝑒𝑛√3𝑥 + (𝑐5 + 𝑐6𝑥)(1)𝑐𝑜𝑠√3𝑥

𝑦 = 𝑐1 + 𝑐2𝑥 + (𝑐3 + 𝑐4𝑥)𝑛√3𝑥 + (𝑐5 + 𝑐6𝑥)𝑐𝑜𝑠√3𝑥

15) (𝐷2 + 16)2𝑦 = 0

(𝑚2 + 16)2 = 0

−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=0
𝑐 = 16

𝑚 = −(0) ± √(0)2 − 4(1)(16)


2(1)

𝑚 = 0 ± √−64
2

𝑚 = 0 ± √64(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
0 ± √64 ∙ √−1
𝑚=
2

𝑖 = √−1
0 ± 8𝑖
𝑚=
2
𝑚 = 0 ± 4𝑖
𝑚1 = 0 + 4𝑖 𝑚2 = 0 + 4𝑖 𝑚3 = 0 − 4𝑖 𝑚4 = 0 − 4𝑖

𝑦 = (𝑐1 + 𝑐2𝑥)0𝑥𝑠𝑒𝑛4𝑥 + (𝑐3 + 𝑐4𝑥)𝑒0𝑥𝑐𝑜𝑠4𝑥


𝑦 = (𝑐1 + 𝑐2𝑥)0𝑠𝑒𝑛4𝑥 + (𝑐3 + 𝑐4𝑥)𝑒0𝑐𝑜𝑠4𝑥
𝑎0 = 1
𝑦 = (𝑐1 + 𝑐2𝑥)(1)𝑠𝑒𝑛4𝑥 + (𝑐3 + 𝑐4𝑥)(1)𝑐𝑜𝑠4𝑥
𝑦 = (𝑐1 + 𝑐2𝑥)𝑛4𝑥 + (𝑐3 + 𝑐4𝑥)𝑐𝑜𝑠4𝑥

16) (𝐷2 − 4𝐷 + 5)2𝑦 = 0


(𝑚2 − 4𝑚 + 5)2 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −4
𝑐=5

𝑚 = −(−4) ± √(−4)2 − 4(1)(5)


2(1)
𝑚 = 4 ± √−4
2

𝑚 = 4 ± √4(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
4 ± √4 ∙ √−1
𝑚=
2

𝑖 = √−1
4 ± 2𝑖
𝑚=
2
𝑚 =2±𝑖
𝑚1 = 2 + 𝑖 𝑚2 = 2 + 𝑖 𝑚3 = 2 – 𝑖 𝑚4 = 2 − 𝑖
𝑦 = (𝑐1 + 𝑐2𝑥)2𝑥𝑠𝑒𝑛𝑥 + (𝑐3 + 𝑐4𝑥)𝑒2𝑥𝑐𝑜𝑠𝑥
𝑦 = [(𝑐1 + 𝑐2𝑥)𝑛𝑥 + (𝑐3 + 𝑐4𝑥)𝑐𝑜𝑠𝑥]𝑒2𝑥

17) (𝐷4 − 8𝐷3 + 32𝐷2 − 64𝐷 + 64) 𝑦 = 0


𝑚4 − 8𝑚3 + 32𝑚2 − 64𝑚 + 64 = 0
𝑚4 − 4𝑚3 − 4𝑚3 + 32𝑚2 − 64𝑚 + 64 = 0
𝑚4 − 4𝑚3 − 4𝑚3 + 8𝑚2 + 16𝑚2 + 8𝑚2 − 64𝑚 + 64 = 0
𝑚4 − 4𝑚3 − 4𝑚3 + 8𝑚2 + 16𝑚2 + 8𝑚2 − 32𝑚 − 32𝑚 + 64 = 0
(𝑚4 − 4𝑚3 + 8𝑚2) + (−4𝑚3 + 16𝑚2 − 32𝑚) + (8𝑚2 − 32𝑚 + 64) = 0
𝑚2(𝑚2 − 4𝑚 + 8) − 4𝑚(𝑚2 − 4𝑚 + 8) + 8(𝑚2 − 4𝑚 + 8) = 0
(𝑚2 − 4𝑚 + 8)(𝑚2 − 4𝑚 + 8) = 0
(𝑚2 − 4𝑚 + 8)2 = 0

−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −4
𝑐=8

𝑚 = −(−4) ± √(−4)2 − 4(1)(8)


2(1)

𝑚 = 4 ± √−16
2

𝑚 = 4 ± √16(−1)
2
√𝑎𝑏 = √𝑎 ∙ √𝑏
4 ± √16 ∙ √−1
𝑚=
2

𝑖 = √−1
4 ± 4𝑖
𝑚=
2
𝑚 = 2 ± 2𝑖
𝑚1 = 2 + 2𝑖 𝑚2 = 2 + 2𝑖 𝑚3 = 2 − 2𝑖 𝑚4 = 2 − 2𝑖
𝑦 = (𝑐1 + 𝑐2𝑥)2𝑥𝑠𝑒𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)𝑒2𝑥𝑐𝑜𝑠2𝑥
𝑦 = [(𝑐1 + 𝑐2𝑥)𝑛2𝑥 + (𝑐3 + 𝑐4𝑥)𝑐𝑜𝑠2𝑥]𝑒2𝑥

18) (𝐷5 − 𝐷4 − 2𝐷3 + 2𝐷2 + 𝐷 − 1) = 0


𝑚5 − 𝑚4 − 2𝑚3 + 2𝑚2 + 𝑚 − 1 = 0
𝐷1 = ±1

𝑚5 𝑚4 𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −1 −2 2 1 −1 𝑚 = 1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
1 0 −2 0 1 𝑚−1=0
1 0 −2 0 1 0
(𝑚 − 1)(𝑚4 − 2𝑚2 + 1) = 0
(𝑚 − 1)(𝑚2 − 1)2 = 0
2
(𝑚 − 1)((𝑚 − 1)(𝑚 + 1)) = 0
𝑚1 − 1 = 0 𝑚2 − 1 = 0 𝑚3 − 1 = 0 𝑚4 + 1 = 0 𝑚5 + 1 = 0
𝑚1 = 1 𝑚2 = 1 𝑚3 = 1 𝑚4 =−1 𝑚5 = −1
𝑦 = 𝑐1𝑒𝑥 + 𝑐2𝑥𝑒𝑥 + 𝑐3𝑥2𝑒𝑥 + 𝑐4𝑒−𝑥 + 𝑐5𝑥𝑒−𝑥
𝑦 = (𝑐1 + 𝑐2𝑥 + 𝑐3𝑥2) + (𝑐4 + 𝑐5𝑥)𝑒−𝑥

19) (𝐷4 + 8𝐷3 + 24𝐷2 + 32𝐷 + 16) = 0


𝑚4 + 8𝑚3 + 24𝑚2 + 32𝑚 + 16 = 0
𝐷16 = ±1, ±2, ±4, ±8, ±16

𝑚4 𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 8 24 32 16 𝑚 = −2
−2 − 12 − 24 − 16 𝑚+2= 0
1 6 12 8 0
(𝑚 + 2)(𝑚3 + 6𝑚2 + 12𝑚 + 8) = 0
𝐷8 = ±1, ±2, ±4, ±8

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 6 12 8 𝑚 = −2 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
−2 −8 −8 𝑚+2=0
1 4 4 0
(𝑚 + 2)(𝑚 + 2)(𝑚2 + 4𝑚 + 4) = 0
(𝑚 + 2)2(𝑚2 + 4𝑚 + 4) = 0

(𝑚 + 2)2(𝑚 + 2)(𝑚 + 2) =

0 (𝑚 + 2)2(𝑚 + 2)2 = 0
(𝑚 + 2)4 = 0

𝑚1 + 2 = 0 𝑚2 + 2 = 0 𝑚3 + 2 = 0 𝑚4 + 2 = 0
𝑚1 = −2 𝑚2 = −2 𝑚3 = −2 𝑚4 = −2

𝑦 = 𝑐1𝑒−2𝑥 + 𝑐2𝑥𝑒−2𝑥 + 𝑐3𝑥2𝑒−2𝑥 + 𝑐4𝑥3𝑒−2𝑥

𝑦 = (𝑐1 + 𝑐2𝑥 + 𝑐3𝑥2 + 𝑐4𝑥3)−2𝑥


20) (𝐷3 − 6𝐷2 + 2𝐷 + 36) = 0
𝑚3 − 6𝑚2 + 2𝑚 + 36 = 0
𝐷36 = ±1, ±2, ±3, ±4, ±6, ±9, ±12, ±18, ±36

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −6 2 36 𝑚 = −2 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
−2 16 − 36 𝑚+2= 0
1 −8 18 0
(𝑚 + 2)(𝑚2 − 8𝑚 + 18) = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −8
𝑐 = 18

𝑚 = −(−8) ± √(−8)2 − 4(1)(18)


2(1)

𝑚 = 8 ± √−8
2
8 ± √8(−1)
𝑚=
2
8 ± √4(2)(−1)
𝑚=
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
8 ± √4 ∙ √2 ∙ √−1
𝑚=
2

𝑖 = √−1

𝑚 = 8 ± 2√2𝑖
2
𝑚 = 4 ± √2𝑖

𝑚1 + 2 = 0

𝑚1 = −2 𝑚2 = 4 + √2𝑖 𝑚3 = 4 − √2𝑖
𝑦 = 𝑐1𝑒 + 𝑐2𝑒 𝑠𝑒𝑛√2𝑥 + 𝑐3𝑒4𝑥𝑐𝑜𝑠√2𝑥
−2𝑥 4𝑥

𝑦 = 𝑐1𝑒−2𝑥 + (𝑐2𝑠𝑒𝑛√2𝑥 + 𝑐3𝑐𝑜𝑠√2𝑥)4𝑥

𝑑2𝑦
21) − 4𝑦 = 0
𝑑𝑥2
𝐷2𝑦 − 4𝑦 = 0
(𝐷2 − 4)𝑦 = 0
𝑚2 − 4 = 0
(𝑚 + 2)(𝑚 − 2) = 0

𝑚1 + 2 = 0 𝑚2 − 2 = 0
𝑚1 = −2 𝑚2 = 2
𝑦 = 𝑐 𝑒−2𝑥 + 𝑐 𝑒2𝑥
1 2

𝑑𝑦
22) − 7𝑦 = 0
𝑑𝑥

𝐷𝑦 − 7𝑦 = 0
(𝐷 − 7)𝑦 = 0

𝑚−7=0
𝑚1 − 7 = 0

𝑚1 = 7
𝑦 = 𝑐1𝑒7𝑥

𝑑3𝑦 𝑑2𝑦 𝑑𝑦
23) + 7 2 + 12 =0
𝑑𝑥3 𝑑𝑥 𝑑𝑥
𝐷3𝑦 + 7𝐷2𝑦 + 12𝐷𝑦 = 0
(𝐷3 + 7𝐷2 + 12𝐷)𝑦 = 0
𝑚3 + 7𝑚2 + 12𝑚 = 0
(𝑚2 + 7𝑚 + 12) = 0
(𝑚 + 4)(𝑚 + 3) = 0
*Encontrando el valor de las raíces “m”
𝑚1 = 0 𝑚2 + 4 = 0 𝑚3 + 3 = 0

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑒−4𝑥 + 𝑐3𝑒−3𝑥


𝑦 = 𝑐1𝑒0 + 𝑐2𝑒−4𝑥 + 𝑐3𝑒−3𝑥

𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑒−4𝑥 + 𝑐3𝑒−3𝑥
𝑦 = 𝑐1 + 𝑐2𝑒−4𝑥 + 𝑐3𝑒−3𝑥
𝑑𝑦
24) 3 ( ) + 11𝑦 = 0
𝑑𝑥
3𝐷𝑦 + 11𝑦 = 0
(3𝐷 + 11)𝑦 = 0

3𝑚 + 11 = 0
3𝑚1 + 11 = 0
3𝑚1 = −11
11
𝑚1 = −
3

11
− 𝑥
𝑦 = 𝑐1 𝑒 3

𝑑2𝑦 𝑑𝑦
25) + − 6𝑦 = 0
𝑑𝑥2 𝑑𝑥
𝐷2𝑦 + 𝐷𝑦 − 6𝑦 = 0
(𝐷2 + 𝐷 − 6)𝑦 = 0
𝑚2 + 𝑚 − 6 = 0
(𝑚 + 3)(𝑚 − 2) = 0
𝑚1 + 3 = 0 𝑚2 − 2 = 0
M1= -3 m2=2

𝑦 = 𝑐1𝑒−3𝑥 + 𝑐2𝑒2𝑥
Ejercicio 3.2 (Deducción de las constantes de integración a partir de
las condiciones iníciales)

1) (𝐷2 + 2𝐷 + 1) = 0 𝑦 = 1, 𝐷𝑦 = −1 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝑚2 + 2𝑚 + 1 = 0
(𝑚 + 1)(𝑚 + 1) = 0
(𝑚 + 1)2 = 0

𝑚1 + 1 = 0 𝑚2 + 1 = 0
M1=-1 m2+1=0

𝑦 = 𝑐1𝑒−𝑥 + 𝑐2𝑥𝑒−𝑥
𝐷𝑥[𝑒𝑢] = 𝑒𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑐1𝑒−𝑥 + 𝑐2𝑥𝑒−𝑥
𝑦 = (𝑐1 + 𝑐2𝑥)−𝑥
𝑢 = 𝑐1 + 𝑐2𝑥 𝑑𝑢 = 𝑐2
𝑣 = 𝑒−𝑥 𝑑𝑣 = −𝑒−𝑥
𝐷𝑦 = (𝑐1 + 𝑐2𝑥)(−𝑒−𝑥) + 𝑒−𝑥(𝑐2)
𝐷𝑦 = −(𝑐1 + 𝑐2𝑥)𝑒−𝑥 + 𝑐2𝑒−𝑥
𝐷𝑦 = 𝑐2𝑒−𝑥 − (𝑐1 + 𝑐2𝑥)−𝑥
𝑦 = 1, 𝐷𝑦 = −1 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝑦 = (𝑐1 + 𝑐2𝑥)−𝑥

1 = (𝑐1 + 𝑐2(0))𝑒−0

𝑎0 = 1
1 = (𝑐1)(1)
C1=1
𝐷𝑦 = 𝑐2𝑒−𝑥 − (𝑐1 + 𝑐2𝑥)−𝑥

−1 = 𝑐2𝑒−0 − (1 + 𝑐2(0))𝑒−0

−1 = 𝑐2(1) − (1)(1)
−1 = 𝑐2 − 1
𝑐2 = 1 – 1
C2=0

𝑦 = (1 + 0(𝑥))−𝑥

𝑦 = (1)−𝑥

𝑦 = 𝑒−𝑥
2) 𝐷2(𝐷 − 1)𝑦 = 0 𝑦 = 2, 𝐷𝑦 = −3, 𝐷2𝑦 = 2 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝑚2(𝑚 − 1) = 0
𝑚3 − 1 = 0
𝑚1 = 0 𝑚2 = 0 𝑚3 = 1

𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑥𝑒0𝑥 + 𝑐3𝑒𝑥


𝑦 = 𝑐1𝑒0 + 𝑐2𝑥𝑒0 + 𝑐3𝑒𝑥
𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑥(1) + 𝑐3𝑒𝑥
𝑦 = 𝑐1 + 𝑐2𝑥 + 𝑐3𝑒𝑥

𝐷𝑥[𝑒𝑢] = 𝑒𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0

𝑎0 = 1
𝑦 = 𝑐1 + 𝑐2𝑥 + 𝑐3𝑒𝑥
𝑢 = 𝑐2 𝑑𝑢 = 0 𝑤 = 𝑐3 𝑑𝑤 = 0
𝑣=𝑥 𝑑𝑣 = 1 𝑧 = 𝑒𝑥 𝑑𝑧 = 𝑒𝑥

𝐷𝑦 = 0 + 𝑐2(1) + 1(0) + 𝑐3𝑒𝑥 + 𝑒𝑥(0)


𝐷𝑦 = 𝑐2 + 𝑐3𝑒𝑥
𝑢 = 𝑐3 𝑑𝑢 = 0
𝑣 = 𝑒𝑥 𝑑𝑣 = 𝑒𝑥
𝐷2𝑦 = 0 + 𝑐3𝑒𝑥 + (0)
𝐷2𝑦 = 𝑐3𝑒𝑥
𝑦 = 2, 𝐷𝑦 = 3, 𝐷2𝑦 = 2 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝐷2𝑦 = 𝑐3𝑒𝑥
2 = 𝑐3𝑒0
𝑎0 = 1
2 = 𝑐3(1)
C3=2
𝐷𝑦 = 𝑐2 + 𝑐3𝑒𝑥
3 = 𝑐2 + 2𝑒0
3 = 𝑐2 + 2(1)
3 = 𝑐2 + 2
3 − 2 = 𝑐2

c2=1

𝑦 = 𝑐1 + 𝑐2𝑥 + 𝑐3𝑒𝑥
2 = 𝑐1 + 1(0) + 2𝑒0
2 = 𝑐1 + 2(1)
2 = 𝑐1 + 2
2 − 2 = 𝑐1

c1=0

𝑦 = 0 + 1𝑥 + 2𝑒𝑥
𝑦 = 𝑥 + 2𝑒𝑥

3) (𝐷3 − 4𝐷2 + 4𝐷) = 0 𝑦 = 1, 𝐷𝑦 = 2, 𝐷2𝑦 = 8 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0


𝑚3 − 4𝑚2 + 4𝑚 = 0
(𝑚2 − 4𝑚 + 4) = 0
(𝑚 − 2)(𝑚 − 2) = 0
(𝑚 − 2)2 = 0
𝑚2 − 2 = 0 𝑚3 − 2 = 0
𝑚1 = 0 𝑚2 = 2 𝑚3 = 2
𝑦 = 𝑐1𝑒0𝑥 + 𝑐2𝑒2𝑥 + 𝑐3𝑥𝑒2𝑥
𝑦 = 𝑐1𝑒0 + 𝑐2𝑒2𝑥 + 𝑐3𝑥𝑒2𝑥
𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑒2𝑥 + 𝑐3𝑥𝑒2𝑥
𝑦 = 𝑐1 + 𝑐2𝑒2𝑥 + 𝑐3𝑥𝑒2𝑥
𝑦 = 𝑐1 + (𝑐2 + 𝑐3𝑥)2𝑥
𝐷𝑥[𝑒𝑢] = 𝑒𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑐1 + (𝑐2 + 𝑐3𝑥)2𝑥
𝑢 = 𝑐2 + 𝑐3𝑥 𝑑𝑢 = 𝑐3
𝑣 = 𝑒2𝑥 𝑑𝑣 = 2𝑒2𝑥
𝐷𝑦 = 0 + (𝑐2 + 𝑐3𝑥)2𝑥(2) + 𝑒2𝑥(𝑐3)
𝐷𝑦 = 2(𝑐2 + 𝑐3𝑥)2𝑥 + 𝑐3𝑒2𝑥
𝑢 = 𝑐2 + 𝑐3𝑥 𝑑𝑢 = 𝑐3 𝑤 = 𝑐3 𝑑𝑤 = 0
𝑣 = 2𝑒2𝑥 𝑑𝑣 = 4𝑒2𝑥 𝑧 = 𝑒2𝑥 𝑑𝑧 = 2𝑒2𝑥

𝐷2𝑦 = 2(𝑐2 + 𝑐3𝑥)2𝑥(2) + 2𝑒2𝑥(𝑐3) + 𝑐3𝑒2𝑥(2) + 𝑒2𝑥(0)


𝐷2𝑦 = 4(𝑐2 + 𝑐3𝑥)2𝑥 + 2𝑐3𝑒2𝑥 + 2𝑐3𝑒2𝑥
𝐷2𝑦 = 4(𝑐2 + 𝑐3𝑥)2𝑥 + 4𝑐3𝑒2𝑥

𝐷2𝑦 = 4(𝑐2 + 𝑐3𝑥)2𝑥 + 4𝑐3𝑒2𝑥


(−2)(𝐷𝑦 = 2(𝑐2 + 𝑐3𝑥)2𝑥 + 𝑐3𝑒2𝑥)
𝐷2𝑦 =
4(𝑐2 + 𝑐3𝑥)2𝑥 + 4𝑐3𝑒2𝑥
−2𝐷𝑦 = −4(𝑐2 + 𝑐3𝑥)𝑒2𝑥 − 2𝑐3𝑒2𝑥
𝐷2𝑦 − 2𝐷𝑦 = 2𝑐3𝑒2𝑥
𝑦 = 1, 𝐷𝑦 = 2, 𝐷2𝑦 = 8 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
8 − 2(2) = 2𝑐3𝑒2(0)
8 − 4 = 2𝑐3𝑒0
𝑎0 = 1
4 = 2𝑐3(1)
4 = 2𝑐3
4
= 𝑐3
2
C3=2
𝐷𝑦 = 2(𝑐2 + 𝑐3𝑥)2𝑥 + 𝑐3𝑒2𝑥

2 = 2(𝑐2 + 2(0))2(0) + 2𝑒2(0)

2 = 2(𝑐2)0 + 2𝑒0
2 = 2𝑐2(1) + 2(1)
2 = 2𝑐2 + 2
2 − 2 = 2𝑐2
0 = 2𝑐2

c2=0

𝑦 = 𝑐1 + (𝑐2 + 𝑐3𝑥)2𝑥

1 = 𝑐1 + (0 + 2(0))2(0)

1 = 𝑐1 + (0)0
1 = 𝑐1 + (0)(1)
C1=1
𝑦 = 1 + (0 + 2𝑥)2𝑥
𝑦 = 1 + (2𝑥)2𝑥
𝑦 = 1 + 2𝑥𝑒2𝑥

4) (𝐷3 − 𝐷2 − 𝐷 + 1) = 0 𝑦 = 0, 𝐷𝑦 = 0, 𝐷2𝑦 = 4 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0


𝑚3 − 𝑚2 − 𝑚 + 1 = 0
𝐷1 = ±1

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −1 −1 1 𝑚 = −1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
−1 2 −1 𝑚+1=0
1 −2 1 0
(𝑚 + 1)(𝑚2 − 2𝑚 + 1) = 0
(𝑚 + 1)(𝑚 − 1)(𝑚 − 1) =

0 (𝑚 + 1)(𝑚 − 1)2 = 0

𝑚1 + 1 = 0 𝑚2 − 1 = 0 𝑚3 − 1 = 0
M1=1 m2=1 m3=1
𝑦 = 𝑐1𝑒−𝑥 + 𝑐2𝑒𝑥 + 𝑐3𝑥𝑒𝑥
𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥)
𝐷𝑥[𝑒𝑢] = 𝑒𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥)
𝑢 = 𝑐1 𝑑𝑢 = 0 𝑤 = 𝑐2 + 𝑐3𝑥 𝑑𝑤 = 𝑐3
𝑣 = 𝑒−𝑥 𝑑𝑣 = −𝑒−𝑥 𝑧 = 𝑒𝑥 𝑑𝑧 = 𝑒𝑥

𝐷𝑦 = 𝑐1(−𝑒−𝑥) + 𝑒−𝑥(0) + (𝑐2 + 𝑐3𝑥)𝑒𝑥 + 𝑒𝑥(𝑐3)


𝐷𝑦 = −𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥) + 𝑐3𝑒𝑥

𝑢 = 𝑐2 + 𝑐3𝑥 𝑑𝑢 = 𝑐3 𝑤 = 𝑐3 𝑑𝑤 = 0 𝑟 = −𝑐1 𝑑𝑟 = 0
𝑣 = 𝑒𝑥 𝑑𝑣 = 𝑒𝑥 𝑧 = 𝑒𝑥 𝑑𝑧 = 𝑒𝑥 𝑠 = 𝑒−𝑥 𝑑𝑠 = −𝑒−𝑥

𝐷2𝑦 = (𝑐2 + 𝑐3𝑥) + 𝑒𝑥(𝑐3) + 𝑐3𝑒𝑥 + 𝑒𝑥(0) − 𝑐1(−𝑒−𝑥) + 𝑒−𝑥(0)


𝐷2𝑦 = (𝑐2 + 𝑐3𝑥) + 𝑐3𝑒𝑥 + 𝑐3𝑒𝑥 + 𝑐1𝑒−𝑥
𝐷2𝑦 = (𝑐2 + 𝑐3𝑥) + 2𝑐3𝑒𝑥 + 𝑐1𝑒−𝑥
𝐷2𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥) + 2𝑐3𝑒𝑥
𝐷2𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥) + 2𝑐3𝑒𝑥
(−1)(𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥))
𝐷2𝑦 = 𝑐1𝑒−𝑥
+ (𝑐2 + 𝑐3𝑥) + 2𝑐3𝑒𝑥
− 𝑦 = −𝑐1𝑒−𝑥 − (𝑐2 + 𝑐3𝑥)
𝐷2𝑦 − 𝑦 = 2𝑐3𝑒𝑥
𝑦 = 0, 𝐷𝑦 = 0, 𝐷2𝑦 = 4 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝐷2𝑦 − 𝑦 = 2𝑐3𝑒𝑥
4 − 0 = 2𝑐3𝑒0
𝑎0 = 1
4 = 2𝑐3(1)
4 = 2𝑐3
4
= 𝑐3
2
𝑐3 = 2

𝑦=
𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥)
𝐷𝑦 = −𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥) + 𝑐3𝑒𝑥
𝐷𝑦 + 𝑦 = 2(𝑐2 + 𝑐3𝑥) + 𝑐3𝑒𝑥
𝐷𝑦 + 𝑦 = 2(𝑐2 + 𝑐3𝑥) + 𝑐3𝑒𝑥

0 + 0 = 2(𝑐2 + 2(0))0 + 2𝑒0

0 = 2(𝑐2 + 0)(1) + 2(1)


0 = 2(𝑐2) + 2
0 = 2𝑐2 + 2
−2 = 2𝑐2
2
− = 𝑐2
2
𝑐2 = −1

𝑦 = 𝑐1𝑒−𝑥 + (𝑐2 + 𝑐3𝑥)

0 = 𝑐1𝑒−0 + (−1 + 2(0))0

0 = 𝑐1𝑒0 + (−1)(1)
0 = 𝑐1(1) − 1
0 = 𝑐1 – 1

𝑐1 = 1
𝑐1 = 1
𝑦 = 1𝑒−𝑥 + (−1 + 2𝑥)
𝑦 = 𝑒−𝑥 + (2𝑥 − 1)

5) (𝐷2 + 1) = 0 𝑦 = 1, 𝐷𝑦 = −1, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 𝜋


𝑚2 + 1 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=0
𝑐=1

𝑚 = −(0) ± √(0)2 − 4(1)(1)


2(1)

𝑚 = 0 ± √−4
2

𝑚 = 0 ± √4(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
0 ± √4 ∙ √−1
𝑚=
2

𝑖 = √−1
0 ± 2𝑖
𝑚=
2
𝑚 =0±𝑖
M1=0+i m2=0-i
𝑦 = 𝑒0(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)
𝑦 = 𝑒0(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)
𝑎0 = 1
𝑦 = (1)(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)

𝑦 = 𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥
𝐷𝑥[𝑆𝑒𝑛𝑢] = 𝐶𝑜𝑠𝑢𝐷𝑥𝑢
𝐷𝑥[𝐶𝑜𝑠𝑢] = −𝑆𝑒𝑛𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥
𝑢 = 𝑐1 𝑑𝑢 = 0 𝑤 = 𝑐2 𝑑𝑤 = 0
𝑣 = 𝑠𝑒𝑛𝑥 𝑑𝑣 = 𝑐𝑜𝑠𝑥 𝑧 = 𝑐𝑜𝑠𝑥 𝑑𝑧 = −𝑠𝑒𝑛𝑥

𝐷𝑦 = 𝑐1(𝑐𝑜𝑠𝑥) + 𝑠𝑒𝑛𝑥(0) + 𝑐2(−𝑠𝑒𝑛𝑥) + 𝑐𝑜𝑠𝑥(0)


𝐷𝑦 = 𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥
𝑦 = 1, 𝐷𝑦 = −1, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 𝜋
𝜋 = 180°
𝐷𝑦 = 𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥
−1 = 𝑐1𝑐(180) − 𝑐2𝑠𝑒𝑛(180)
−1 = 𝑐1(−1) − 𝑐2(0)
−1 = −𝑐1
(−1)(−𝑐1 = −1)
𝑐1 = 1
𝑦 = 𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥
1 = 1𝑠(180) + 𝑐2𝑐𝑜𝑠(180)
1 = 1(0) + 𝑐2(−1)
1 = −𝑐2
(−1)(1 = −𝑐2)
𝑐2 = −1
𝑦 = 1𝑠𝑒𝑛𝑥 + (−1)𝑠𝑥
𝑦 = 𝑠𝑒𝑛(𝑥) − 𝑐𝑜𝑠(𝑥)
𝜋
6) (𝐷2 + 9) = 0 𝑦 = 2, 𝐷𝑦 = 0, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 =
6
𝑚2 + 9 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=0
𝑐=9

𝑚 = −(0) ± √(0)2 − 4(1)(9)


2(1)

𝑚 = 0 ± √−36
2

𝑚 = 0 ± √36(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
0 ± √36 ∙ √−1
𝑚=
2
𝑖 = √−1
0 ± 6𝑖
𝑚=
2
𝑚 = 0 ± 3𝑖
M1=0+3i m2=0-3i

𝑦 = 𝑒0(𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥)
𝑦 = 𝑒0(𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥)
𝑎0 = 1
𝑦 = (1)(𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥)
𝑦 = 𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥
𝐷𝑥[𝑆𝑒𝑛𝑢] = 𝐶𝑜𝑠𝑢𝐷𝑥𝑢
𝐷𝑥[𝐶𝑜𝑠𝑢] = −𝑆𝑒𝑛𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥
𝑢 = 𝑐1 𝑑𝑢 = 0 𝑤 = 𝑐2 𝑑𝑤 = 0
𝑣 = 𝑠𝑒𝑛3𝑥 𝑑𝑣 = 3𝑐𝑜𝑠3𝑥 𝑧 = 𝑐𝑜𝑠3𝑥 𝑑𝑧 = −3𝑠𝑒𝑛3𝑥
𝐷𝑦 = 𝑐1(3𝑐𝑜𝑠3𝑥) + 𝑠𝑒𝑛3𝑥(0) + 𝑐2(−3𝑠𝑒𝑛3𝑥) + 𝑐𝑜𝑠3𝑥(0)
𝐷𝑦 = 3𝑐1𝑐𝑜𝑠3𝑥 − 3𝑐2𝑠𝑒𝑛3𝑥
𝜋
𝑦 = 2, 𝐷𝑦 = 0, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 =
6
𝜋 = 180°
𝐷𝑦 = 3𝑐1𝑐𝑜𝑠3𝑥 − 3𝑐2𝑠𝑒𝑛3𝑥
180 180
0 = 3𝑐1𝑐𝑜𝑠3 ( ) − 3𝑐2𝑠𝑒𝑛3 ( )
6 6
0 = 3𝑐1𝑐𝑜𝑠3(30) − 3𝑐2𝑠𝑒𝑛3(30)
0 = 3𝑐1𝑐(90) − 3𝑐2𝑠𝑒𝑛(90)
0 = 3𝑐1(0) − 3𝑐2(1)
0 = −3𝑐2
0
− = 𝑐2
3
C 2=0
𝑦 = 𝑐1𝑠𝑒𝑛3𝑥 + 𝑐2𝑐𝑜𝑠3𝑥
180 180
2 = 𝑐1𝑠𝑒𝑛3 ( ) + 0 (𝑐𝑜𝑠3 ( ))
6 6

2 = 𝑐1𝑠𝑒𝑛3(30)
2 = 𝑐1𝑠(90)
2 = 𝑐1(1)
C1=2
𝑦 = 2(𝑠𝑒𝑛3𝑥) + 0(𝑐𝑜𝑠3𝑥)

𝑦 = 2𝑠𝑒𝑛3𝑥
7) (𝐷2 + 2𝐷 + 2) = 0 𝑦 = 0, 𝐷𝑦 = 1, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝑚2 + 2𝑚 + 2 = 0
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏=2
𝑐=2

𝑚 = −(2) ± √(2)2 − 4(1)(2)


2(1)
𝑚 = −2 ± √−4
2

𝑚 = −2 ± √4(−1)
2

√𝑎𝑏 = √𝑎 ∙ √𝑏
−2 ± √4 ∙ √−1
𝑚=
2
𝑖 = √−1
−2 ± 2𝑖
𝑚=
2
𝑚 = −1 ± 𝑖

M1=-1+i m2=-1-i
𝑦 = 𝑒−(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)
𝐷𝑥[𝑆𝑒𝑛𝑢] = 𝐶𝑜𝑠𝑢𝐷𝑥𝑢
𝐷𝑥[𝐶𝑜𝑠𝑢] = −𝑆𝑒𝑛𝑢𝐷𝑥𝑢
𝐷𝑥(𝑢 ∙ 𝑣) = 𝑢𝑑𝑣 + 𝑣𝑑𝑢
(𝑢)𝑛 = 𝑛(𝑢)𝑛−1𝑑𝑢
(𝑐) = 0
𝑎0 = 1
𝑦 = 𝑒−(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)
𝑢 = 𝑒−𝑥 𝑑𝑢 = −𝑒−𝑥
𝑣 = 𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥 𝑑𝑣 = 𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥
𝐷𝑦 = 𝑒−(𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥) + (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)(−𝑒−𝑥)
𝐷𝑦 = 𝑒−(𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥) − 𝑒−𝑥(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)
𝑦 = 0, 𝐷𝑦 = 1, 𝑐𝑢𝑎𝑛𝑑𝑜 𝑥 = 0
𝑦 = 𝑒−(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)

0 = 𝑒−0(𝑐1𝑠𝑒𝑛(0) + 𝑐2𝑐𝑜𝑠(0))

0 = 𝑒0(𝑐1(0) + 𝑐2(1))
𝑎0 = 1
0 = (1)(𝑐2)

C2=0
𝐷𝑦 = 𝑒−(𝑐1𝑐𝑜𝑠𝑥 − 𝑐2𝑠𝑒𝑛𝑥) − 𝑒−𝑥(𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)

1 = 𝑒−0 (𝑐1𝑐(0) − 0(𝑠𝑒𝑛(0))) − 𝑒−0 (𝑐1𝑠𝑒𝑛(0) + 0(𝑐𝑜𝑠(0)))

1 = 𝑒0(𝑐1(1)) − 𝑒0(𝑐1(0))

1 = (1)(𝑐1) − (1)(0)
1 = 𝑐1

c1=1

𝑦 = 𝑒−(1𝑠𝑒𝑛𝑥 + 0𝑐𝑜𝑠𝑥)
𝑦 = 𝑒−𝑥(𝑠𝑒𝑛𝑥)
𝑦 = 𝑒−𝑥𝑠𝑒𝑛𝑥
Ejercicio 3.3 (Ecuaciones Diferenciales no Homogéneas por el método
de coeficientes indeterminados)

1) (𝐷2 − 𝐷 − 2) = 𝑒3𝑥
(𝐷2 − 𝐷 − 2)𝑦 = 0
𝑚2 + 2𝑚 + 2 = 0
(𝑚 + 1)(𝑚 − 2) = 0
𝑚1 + 1 = 0 𝑚2 − 2 = 0
M1=-1 m2=2
𝑦𝑐 = 𝑐1𝑒 + 𝑐2𝑒2𝑥
−𝑥

𝑦𝑝 = 𝐴𝑒3𝑥
(𝐷2 − 𝐷 − 2)𝑦 = 𝑒3𝑥
(𝐷2 − 𝐷 − 2) 𝑦𝑝 = 𝑒3𝑥

(𝐷2 − 𝐷 − 2) 𝐴𝑒3𝑥 = 𝑒3𝑥


𝐷2𝐴𝑒3𝑥 − 𝐷𝐴𝑒3𝑥 − 2𝐴𝑒3𝑥 = 𝑒3𝑥
𝐷2𝐴𝑒3𝑥 − 𝐷𝐴𝑒3𝑥 − 2𝐴𝑒3𝑥 = 𝑒3𝑥
3𝐷𝐴𝑒3𝑥 − 3𝐴𝑒3𝑥 − 2𝐴𝑒3𝑥 = 𝑒3𝑥
9𝐴𝑒3𝑥 − 5𝐴𝑒3𝑥 = 𝑒3𝑥
4𝐴𝑒3𝑥 = 𝑒3𝑥
𝑒3𝑥
𝐴 = 4𝑒3𝑥

1
𝐴=
4

𝑦𝑝 = 𝐴𝑒3𝑥

1
𝑦𝑝 =𝑒3𝑥
4

𝑦𝐺 = 𝑦𝑐 + 𝑦𝑝

−𝑥 2𝑥 1 3𝑥
𝑦𝐺1= 𝑐 𝑒+ 𝑐 𝑒+𝑒
2
4
2) (𝐷2 − 𝐷 − 2) = 𝑠𝑒(2𝑥)
(𝐷2 − 𝐷 − 2)𝑦 = 0
𝑚2 + 2𝑚 + 2 = 0
(𝑚 + 1)(𝑚 − 2) = 0

𝑚1 + 1 = 0 𝑚2 − 2 = 0
M1=-1 m2=2

𝑦 = 𝑐 𝑒−𝑥 + 𝑐 𝑒2𝑥
𝑐 1 2

𝑦𝑝 = 𝐴𝑠(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)

(𝐷2 − 𝐷 − 2)𝑦 = 𝑠(2𝑥)

(𝐷2 − 𝐷 − 2)𝑦𝑝 = 𝑠𝑒(2𝑥)

(𝐷2 − 𝐷 − 2)(𝐴𝑠(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) = 𝑠(2𝑥)

𝐷2(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) − 𝐷(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) − 2(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) = 𝑠𝑒𝑛(2𝑥)

𝐷2(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) − 𝐷(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) − 2(𝐴𝑠𝑒𝑛(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)) = 𝑠𝑒𝑛(2𝑥)

𝐷(2𝐴𝑐𝑜𝑠(2𝑥) − 2𝐵𝑠𝑒𝑛(2𝑥)) − (2𝐴𝑐𝑜𝑠(2𝑥) − 2𝐵𝑠𝑒𝑛(2𝑥)) − 2𝐴𝑠𝑒𝑛(2𝑥) − 2𝐵𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(2𝑥)

(−4𝐴𝑠𝑒𝑛(2𝑥) − 4𝐵𝑐𝑜𝑠(2𝑥)) − 2𝐴𝑐𝑜𝑠(2𝑥) + 2𝐵𝑠𝑒𝑛(2𝑥) − 2𝐴𝑠𝑒𝑛(2𝑥) − 2𝐵𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(2𝑥)


−4𝐴𝑠(2𝑥) − 4𝐵𝑐𝑜𝑠(2𝑥) − 2𝐴𝑐𝑜𝑠(2𝑥) + 2𝐵𝑠𝑒𝑛(2𝑥) − 2𝐴𝑠𝑒𝑛(2𝑥) − 2𝐵𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(2𝑥)

−6𝐴𝑠𝑒𝑛(2𝑥) − 6𝐵𝑐𝑜𝑠(2𝑥) − 2𝐴𝑐𝑜𝑠(2𝑥) + 2𝐵𝑠𝑒𝑛(2𝑥) = 𝑠𝑒𝑛(2𝑥)


(−6𝐴 + 2𝐵)𝑠𝑒𝑛(2𝑥) + (−6𝐵 − 2𝐴)𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(2𝑥)
(2𝐵 − 6𝐴)𝑠(2𝑥) + (−6𝐵 − 2𝐴)𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(2𝑥)
2𝐵 − 6𝐴 = 1
−6𝐵 − 2𝐴 = 0
(3)(2𝐵 − 6𝐴 = 1)
−6𝐵 − 2𝐴 = 0
6𝐵 − 18𝐴 = 3

−6𝐵 − 2𝐴 = 0
−20𝐴 = 3
3
𝐴=−
2
2𝐵 − 6𝐴 = 1 ) = 1
3
2𝐵 − 6 (−
2
0
18
2𝐵 + =1
20
9
2𝐵 + =1
10
9
2𝐵 = 1 −
10
10 9
2𝐵 = −
10 10
10 − 9
2𝐵 =
10
1
2𝐵 =
10
1
𝐵=
10(2)
1
𝐵=
20

𝑦𝑝 = 𝐴𝑠(2𝑥) + 𝐵𝑐𝑜𝑠(2𝑥)

3 1
𝑦𝑝 = − 20 𝑠 (2𝑥) + 20 𝑐𝑜𝑠(2𝑥)

−𝑥 2𝑥 3 1
𝑦𝐺1= 𝑐 𝑒+ 𝑐 𝑒−𝑠
2 (2𝑥) +𝑐𝑜𝑠(2𝑥)
20 20

3) (𝐷3 − 6𝐷2 + 11𝐷 − 6) = 2𝑥𝑒−𝑥


(𝐷3 − 6𝐷2 + 11𝐷 − 6)𝑦 = 0
𝑚3 − 6𝑚2 + 11𝑚 − 6 = 0
𝐷6 = ±1, ±2, ±3, ±6

𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −6 11 −6 𝑚 = 1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
1 −5 6 𝑚−1=0
1 −5 6 0

(𝑚 − 1)(𝑚2 − 5𝑚 + 6) = 0
(𝑚 − 1)(𝑚 − 2)(𝑚 − 3) = 0
𝑚1 − 1 = 0 𝑚2 − 2 = 0 𝑚3 − 3 = 0
M1=1 m2=2 m3=3
𝑦𝑐 = 𝑐1𝑒 + 𝑐2𝑒 + 𝑐3𝑒3𝑥
𝑥 2𝑥

𝑦𝑝 = (𝐴𝑥 + 𝐵)𝑒−𝑥

(𝐷3 − 6𝐷2 + 11𝐷 − 6)𝑦 = 2𝑥𝑒−𝑥


(𝐷3 − 6𝐷2 + 11𝐷 − 6)𝑦𝑝 = 2𝑥𝑒−𝑥

(𝐷3 − 6𝐷2 + 11𝐷 − 6)((𝐴𝑥 + 𝐵)𝑒−𝑥) = 2𝑥𝑒−𝑥

𝐷3(𝐴𝑥 + 𝐵)𝑒−𝑥 − 6𝐷2(𝐴𝑥 + 𝐵)𝑒−𝑥 + 11𝐷(𝐴𝑥 + 𝐵)𝑒−𝑥 − 6(𝐴𝑥 + 𝐵)𝑒−𝑥 = 2𝑥𝑒−𝑥


3𝐴𝑒−𝑥 − 𝐴𝑥𝑒−𝑥 − 𝐵𝑒−𝑥

𝐴𝑥𝑒−𝑥 + 𝐵𝑒−𝑥 − 2𝐴𝑒−𝑥

𝐴𝑒−𝑥 − 𝐴𝑥𝑒−𝑥 − 𝐵𝑒−𝑥


𝐷3(𝐴𝑥 + 𝐵)𝑒−𝑥 − 6𝐷2(𝐴𝑥 + 𝐵)𝑒−𝑥 + 11𝐷(𝐴𝑥 + 𝐵)𝑒−𝑥 − 6(𝐴𝑥 + 𝐵)𝑒−𝑥 = 2𝑥𝑒−𝑥
3𝐴𝑒−𝑥 − 𝐴𝑥𝑒−𝑥 − 𝐵𝑒−𝑥 − 6(𝐴𝑥𝑒−𝑥 + 𝐵𝑒−𝑥 − 2𝐴𝑒−𝑥) + 11(𝐴𝑒−𝑥 − 𝐴𝑥𝑒−𝑥 − 𝐵𝑒−𝑥) →
→ −6(𝐴𝑥𝑒−𝑥 + 𝐵𝑒−𝑥) = 2𝑥𝑒−𝑥

3𝐴𝑒−𝑥 − 𝐴𝑥𝑒−𝑥 − 𝐵𝑒−𝑥 − 6𝐴𝑥𝑒−𝑥 − 6𝐵𝑒−𝑥 + 12𝐴𝑒−𝑥 + 11𝐴𝑒−𝑥 − 11𝐴𝑥𝑒−𝑥 →


→ −11𝐵𝑒−𝑥 − 6𝐴𝑥𝑒−𝑥 − 6𝐵𝑒−𝑥 = 2𝑥𝑒−𝑥

26𝐴𝑒−𝑥 − 24𝐴𝑥𝑒−𝑥 − 24𝐵𝑒−𝑥 = 2𝑥𝑒−𝑥


(26𝐴 − 24𝐵)𝑒−𝑥 + (−24𝐴)−𝑥 = 2𝑥𝑒−𝑥

1
26𝐴 − 24𝐵 = 0 − 24𝐴 = 2 26 (− ) − 24𝐵 = 0
12
2 26
−24𝐴 = 2 𝐴=−
24 − − 24𝐵 = 0
12
1 13
𝐴=−
12 − − 24𝐵 = 0
6
13
−24𝐵 =
6
13
𝐵=
(−24)6
13
𝐵=−
144

𝑦𝑝 = (𝐴𝑥 + 𝐵)𝑒−𝑥
1 13
𝑦𝑝 = (− 𝑥− )
1
2 𝑒−𝑥
1 14413
𝑦𝑝 = −𝑥𝑒−𝑥 −
12 𝑒−𝑥
144

1 13
𝑦𝐺1= 𝑐 𝑒 𝑥 + 𝑐2 𝑒+
2𝑥
𝑐 𝑒−
3
3𝑥 −𝑥
12 𝑥𝑒−𝑒
−𝑥
144
4) 𝐷2𝑦 = 9𝑥2 + 2𝑥 − 1
𝐷2𝑦 = 0
(𝐷2)𝑦 = 0
𝑚2 = 0
M1=0 m2=0
𝑦𝑐 = 𝑐1𝑒0𝑥 + 𝑐2𝑥𝑒0𝑥
𝑦𝑐 = 𝑐1𝑒0 + 𝑐2𝑥𝑒0
𝑎0 = 1
𝑦𝑐 = 𝑐1(1) + 𝑐2𝑥(1)
𝑦𝑐 = 𝑐1 + 𝑐2𝑥

𝑦𝑝 = 𝐴𝑥2 + 𝐵𝑥 + 𝐶
𝑦𝑝 = (𝐴𝑥2 + 𝐵𝑥 + 𝐶)2

𝑦𝑝 = 𝐴𝑥4 + 𝐵𝑥3 + 𝐶𝑥2

(𝐷2)𝑦 = 0
(𝐷2)𝑦𝑝 = 0

𝐷2(𝐴𝑥4 + 𝐵𝑥3 + 𝐶𝑥2) = 9𝑥2 + 2𝑥 − 1


𝐷2(𝐴𝑥4 + 𝐵𝑥3 + 𝐶𝑥2) = 9𝑥2 + 2𝑥 − 1
(4𝐴𝑥3 + 3𝐵𝑥2 + 2𝐶𝑥) = 9𝑥2 + 2𝑥 − 1
12𝐴𝑥2 + 6𝐵𝑥 + 2𝐶 = 9𝑥2 + 2𝑥 − 1
(12𝐴)2 + (6𝐵)𝑥 + 2𝐶 = 9𝑥2 + 2𝑥 − 1
12𝐴 = 9 12𝐴 = 9 6𝐵 = 2 2𝐶 = −1
9
6𝐵 = 2 𝐴= 2 1
12 𝐵= 𝐶=−
6 2
3 1
2𝐶 = −1 𝐴= 𝐵=
4 3

𝑦𝑝 = 𝐴𝑥4 + 𝐵𝑥3 + 𝐶𝑥2

311
𝑦𝑝 =𝑥4
4 +𝑥33−𝑥2 2

3 4 1 3 1 2
𝑦𝐺12= 𝑐 + 𝑐 𝑥 +𝑥 +𝑥 −𝑥
4 3 2
5) (𝐷 − 5) = 2𝑒5𝑥
(𝐷 − 5)𝑦 = 0
𝑚−5=0
𝑚1 − 5 = 0
M1=5
𝑦𝑐 = 𝑐1𝑒5𝑥

𝑦𝑝 = 𝐴𝑒5𝑥
𝑦𝑝 = (𝐴𝑒5𝑥)

𝑦𝑝 = 𝐴𝑥𝑒5𝑥

(𝐷 − 5)𝑦 = 2𝑒5𝑥
(𝐷 − 5)𝑦𝑝 = 2𝑒5𝑥

(𝐷 − 5)𝐴𝑥𝑒5𝑥 = 2𝑒5𝑥

𝐷𝐴𝑥𝑒5𝑥 − 5𝐴𝑥𝑒5𝑥 = 2𝑒5𝑥


𝐷𝐴𝑥𝑒5𝑥 − 5𝐴𝑥𝑒5𝑥 = 2𝑒5𝑥
+ 𝐴𝑒5𝑥 − 5𝐴𝑥𝑒5𝑥
5𝐴𝑥𝑒5𝑥 = 2𝑒5𝑥
𝐴𝑒5𝑥 = 2𝑒5𝑥

2𝑒5𝑥
𝐴=
𝑒5𝑥

A=2

𝑦𝑝 = 𝐴𝑥𝑒5𝑥

𝑦𝑝 = 2𝑥𝑒5𝑥

𝑦𝐺 = 𝑐1𝑒5𝑥 + 2𝑥𝑒5𝑥
𝑦𝐺 = (𝑐1 + 2𝑥)5𝑥
6) (𝐷 − 5) = (𝑥 − 1)𝑒𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)

(𝐷 − 5)𝑦 = 0

𝑚−5=0

𝑚1 − 5 = 0

M1=5
𝑦𝑐 = 𝑐1𝑒5𝑥

𝑦𝑝 = (𝐴𝑥 + 𝐵)𝑠𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)

(𝐷 − 5)𝑦 = (𝑥 − 1)𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥) (𝐷


− 5)𝑦𝑝 = (𝑥 − 1)𝑠𝑒𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)

(𝐷 − 5)((𝐴𝑥 + 𝐵)𝑠𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)) = (𝑥 − 1)𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)


((𝐴𝑥 + 𝐵)𝑠𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)) − 5((𝐴𝑥 + 𝐵)𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)) →
→ = (𝑥 − 1)𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)

((𝐴𝑥 + 𝐵)𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)) 𝑝𝑎𝑟𝑎 𝐷 𝑜 𝑦′ = →

→ (𝐴𝑥 + 𝐵)𝑐𝑜𝑠(𝑥) + 𝐴𝑠𝑒𝑛(𝑥) − (𝐶𝑥 + 𝐷)𝑠𝑒𝑛(𝑥) + 𝐶𝑐𝑜𝑠(𝑥)


(𝐴𝑥 + 𝐵)𝑐(𝑥) + 𝐴𝑠𝑒𝑛(𝑥) − (𝐶𝑥 + 𝐷)𝑠𝑒𝑛(𝑥) + 𝐶𝑐𝑜𝑠(𝑥) − 5(𝐴𝑥 + 𝐵)𝑠𝑒𝑛(𝑥) →
→ −5(𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥) = (𝑥 − 1)𝑠𝑒𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)

𝐴𝑥𝑐(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐴𝑠𝑒𝑛(𝑥) − 𝐶𝑥𝑠𝑒𝑛(𝑥) − 𝐷𝑠𝑒𝑛(𝑥) + 𝐶𝑐𝑜𝑠(𝑥) − 5𝐴𝑥𝑠𝑒𝑛(𝑥) →


→ −5𝐵𝑠(𝑥) − 5𝐶𝑥𝑐𝑜𝑠(𝑥) − 5𝐷𝑐𝑜𝑠(𝑥) = (𝑥 − 1)𝑠𝑒𝑛(𝑥) + (𝑥 + 1)𝑐𝑜𝑠(𝑥)

𝐴𝑥𝑐(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐴𝑠𝑒𝑛(𝑥) − 𝐶𝑥𝑠𝑒𝑛(𝑥) − 𝐷𝑠𝑒𝑛(𝑥) + 𝐶𝑐𝑜𝑠(𝑥) − 5𝐴𝑥𝑠𝑒𝑛(𝑥) →


→ −5𝐵𝑠(𝑥) − 5𝐶𝑥𝑐𝑜𝑠(𝑥) − 5𝐷𝑐𝑜𝑠(𝑥) = 𝑥𝑠𝑒𝑛(𝑥) − 𝑠𝑒𝑛(𝑥) + 𝑥𝑐𝑜𝑠(𝑥) + 𝑐𝑜𝑠(𝑥)

(−5𝐴 − 𝐶)𝑥𝑠(𝑥) + (𝐴 − 𝐷 − 5𝐵)𝑠𝑒𝑛(𝑥) + (𝐴 − 5𝐶)𝑥𝑐𝑜𝑠(𝑥) →


→ +(𝐵 + 𝐶 − 5𝐷)𝑐𝑜𝑠(𝑥) = 𝑥𝑠𝑒𝑛(𝑥) − 𝑠𝑒𝑛(𝑥) + 𝑥𝑐𝑜𝑠(𝑥) + 𝑐𝑜𝑠(𝑥)
−5𝐴 − 𝐶 = 1
𝐴 − 𝐷 − 5𝐵 = −1
𝐴 − 5𝐶 = 1

𝐵 + 𝐶 − 5𝐷 = 1
(5)(𝐴 − 5𝐶 = 1)
−5𝐴 − 𝐶 = 1
5𝐴 − 25𝐶 = 5
−5𝐴 − 𝐶 = 1
−26𝐶 = 6
6
𝐶=−
26
3
𝐶=−
13
𝐴 − 5𝐶 = 1
3
𝐴 − 5 (− )=1
1
3
15
𝐴+ =1
13
15
𝐴=1−
13
13 15
𝐴= −
13 13
𝐴 = 13 − 15
13
2
𝐴=−
13
(5)(𝐵 + 𝐶 − 5𝐷 = 1)
−5𝐵 + 𝐴 − 𝐷 = −1
5𝐵 + 5𝐶 − 25𝐷 = 5
−5𝐵 + 𝐴 − 𝐷 =
−1 5𝐶 + 𝐴 − 26𝐷
=4

5 (− 3 ) + 2
) − 26𝐷 = 4
(− 13
15 13
2
− − − 26𝐷 = 4
13 13
−15 − 2
13 − 26𝐷 = 4
17
− − 26𝐷 = 4
13
17
−26𝐷 = 4 +
13
52 17
−26𝐷 = +
13 13
52 + 17
−26𝐷 =
13
69
−26𝐷 =
13
69
𝐷=
13(−26)
69
𝐷=−
338
𝐵 + 𝐶 − 5𝐷 = 1
3 69
𝐵+ )−5 )=1
(− (− 338
13
3 345
𝐵− + =1
1 338
3
267
𝐵+ =1
338
267
𝐵 =1−
338
33 267
8 −
𝐵= 338
33
8
338 − 267
𝐵=
338
71
𝐵=
338

𝑦𝑝 = (𝐴𝑥 + 𝐵)𝑠𝑒𝑛(𝑥) + (𝐶𝑥 + 𝐷)𝑐𝑜𝑠(𝑥)

2 71 3 69
𝑦𝑝 = (− 13 𝑥 + 338) 𝑠 (𝑥) + (− 13 𝑥 − 338) 𝑐𝑜𝑠(𝑥)

5𝑥 2 71 3 69
𝑦𝐺1= 𝑐 𝑒+ (−𝑥 +) 𝑠𝑒𝑛(𝑥) + (−𝑥 −) 𝑐𝑜𝑠(𝑥)
13338 13338

7) (𝐷 − 5) = 3𝑒𝑥 − 2𝑥 + 1
(𝐷 − 5)𝑦 = 0
𝑚−5=0
𝑚1 − 5 = 0
M1=5
𝑦𝑐 = 𝑐1𝑒5𝑥

𝑦𝑝 = 𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶

(𝐷 − 5)𝑦 = 3𝑒𝑥 − 2𝑥 + 1
(𝐷 − 5) = 3𝑒𝑥 − 2𝑥 + 1

(𝐷 − 5)(𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶) = 3𝑒𝑥 − 2𝑥 + 1
(𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶) − 5(𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶) = 3𝑒𝑥 − 2𝑥 + 1

(𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶) − 5(𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶) = 3𝑒𝑥 − 2𝑥 + 1


𝐴𝑒𝑥 + 𝐵 − 5𝐴𝑒𝑥 − 5𝐵𝑥 − 5𝐶 = 3𝑒𝑥 − 2𝑥 + 1
𝐵 − 4𝐴𝑒𝑥 − 5𝐵𝑥 − 5𝐶 = 3𝑒𝑥 − 2𝑥 + 1 (−4𝐴)
+ (−5𝐵)𝑥 + 𝐵 − 5𝐶 = 3𝑒𝑥 − 2𝑥 + 1
−4𝐴 = 3 − 4𝐴 = 3 − 5𝐵 = −2 𝐵 − 5𝐶 = 1
3 −2
−5𝐵 = −2 𝐴=− 𝐵= − 5𝐶 = 1 − 𝐵
4 −5
2 2
𝐵 − 5𝐶 = 1 𝐵= − 5𝐶 = 1 −
5 5
5 2
−5𝐶 = −
5 5
3
𝐶=
(−5)5
3
𝐶=−
25
𝑦𝑝 = 𝐴𝑒𝑥 + 𝐵𝑥 + 𝐶

323
𝑦𝑝 = −𝑒𝑥
4 +𝑥 −525

5𝑥 3 2 3
𝑦𝐺1= 𝑐 𝑒−𝑒 +𝑥 𝑥−
4 525

8) (𝐷 − 5) = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥
( 𝐷 − 5 )𝑦 = 0
𝑚−5=0
𝑚1 − 5 = 0
M1=5
𝑦𝑐 = 𝑐1𝑒5𝑥

𝑦𝑝 = (𝐴𝑥2 + 𝐵𝑥 + 𝐶) − (𝐷𝑥 + 𝐸)𝑒5𝑥


𝑦𝑝 = (𝐴𝑥2 + 𝐵𝑥 + 𝐶) − ((𝐷𝑥 + 𝐸)𝑒5𝑥)𝑥

𝑦𝑝 = (𝐴𝑥2 + 𝐵𝑥 + 𝐶) − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥

(𝐷 − 5)𝑦 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥
(𝐷 − 5)𝑦𝑝 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥

(𝐷 − 5)((𝐴𝑥2 + 𝐵𝑥 + 𝐶) − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥) = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥


((𝐴𝑥2 + 𝐵𝑥 + 𝐶)𝑥 − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥) − 5((𝐴𝑥2 + 𝐵𝑥 + 𝐶)𝑥 − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥) →

→ = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥

→ = (𝐴𝑥2 + 𝐵𝑥 + 𝐶) + 𝑒𝑥(2𝐴𝑥 + 𝐵) − 5(𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥 − 𝑒5𝑥(2𝐷𝑥 + 𝐸)

((𝐴𝑥2 + 𝐵𝑥 + 𝐶)𝑥 − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥) − 5((𝐴𝑥2 + 𝐵𝑥 + 𝐶)𝑥 − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥) →

→ = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥

(𝐴𝑥2 + 𝐵𝑥 + 𝐶)𝑒𝑥 + (2𝐴𝑥 + 𝐵) − 5(𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥 − 𝑒5𝑥(2𝐷𝑥 + 𝐸) →

→ −5𝐴𝑥2𝑒𝑥 − 5𝐵𝑥𝑒𝑥 − 5𝐶𝑒𝑥 + 5𝐷𝑥2𝑒5𝑥 + 5𝐸𝑥𝑒5𝑥 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥

𝐴𝑥2𝑒𝑥 + 𝐵𝑥𝑒𝑥 + 𝐶𝑒𝑥 + 2𝐴𝑥𝑒𝑥 + 𝐵𝑒𝑥 − 5𝐷𝑥2𝑒5𝑥 − 5𝐸𝑥𝑒5𝑥− 2𝐷𝑥𝑒5𝑥 − 𝐸𝑒5𝑥 →


→ −5𝐴𝑥2𝑒𝑥 − 5𝐵𝑥𝑒𝑥 − 5𝐶𝑒𝑥 + 5𝐷𝑥2𝑒5𝑥 + 5𝐸𝑥𝑒5𝑥 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥
−4𝐴𝑥2𝑒𝑥 − 4𝐵𝑥𝑒𝑥 − 4𝐶𝑒𝑥 + 2𝐴𝑥𝑒𝑥 + 𝐵𝑒𝑥 − 2𝐷𝑥𝑒5𝑥 − 𝐸𝑒5𝑥 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥
(−4𝐴)𝑥2𝑒𝑥 + (−2𝐷)5𝑥 + (2𝐴 − 4𝐵)𝑥𝑒𝑥 + (−𝐸)𝑒5𝑥 + (𝐵 − 4𝐶)𝑒𝑥 = 𝑥 2 𝑒 𝑥 − 𝑥𝑒5𝑥
−4𝐴 = 1 − 4𝐴 = 1 − 2𝐷 = −1 2𝐴 − 4𝐵 = 0 𝐵 − 4𝐶 = 0
1 −1
−2𝐷 = −1 𝐴=− 𝐷= 4𝐵 = 2𝐴 4𝐶 = 𝐵
4 −2
1 1 1
2𝐴 − 4𝐵 = 0 𝐷= 4𝐵 = 2 (− ) 4𝐶 = −
2 4 8
2 1
−𝐸 = 0 4𝐵 = − 𝐶=−
4 8(4)
1 1
𝐸=0 4𝐵 = − 𝐶=−
2 32
1
𝐵 − 4𝐶 = 0 𝐵=−
2(4)
1
𝐵=−
8

𝑦𝑝 = (𝐴𝑥2 + 𝐵𝑥 + 𝐶) − (𝐷𝑥2 + 𝐸𝑥)𝑒5𝑥


1 1 1 1
𝑦 = (− 𝑥2 − 𝑥 − ) 𝑒𝑥 − ( 𝑥2 + 0𝑥) 𝑒5𝑥
𝑝
4 8 32 2
1 2 1 1 𝑥 1
𝑦 = (− 𝑥 − 𝑥 − ) 𝑒 − ( 𝑥2) 𝑒5𝑥
𝑝
4 8 32 2

1 1 1 1
𝑦𝑝 = − ( 𝑥2 +𝑥 +) 𝑒𝑥 −
4832 𝑥2𝑒5𝑥
2

5𝑥 1 2 1 1 𝑥 1 2 5𝑥
𝑦𝐺1= 𝑐 𝑒− ( 𝑥 +𝑥 +) 𝑒 −𝑥 𝑒
4 832 2

9) (𝐷 − 1) = 𝑠𝑒(𝑥) + 𝑐𝑜𝑠(2𝑥)
(𝐷 − 1)𝑦 = 0
𝑚−1=0
𝑚1 − 1 = 0

𝑚1 = 1

M1=1
𝑦𝑐 = 𝑐1𝑒𝑥

𝑦𝑝 = 𝐴𝑠(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐶𝑠𝑒𝑛(2𝑥) + 𝐷𝑐𝑜𝑠(2𝑥)

(𝐷 − 1)𝑦 = 𝑠(𝑥) + 𝑐𝑜𝑠(2𝑥) (𝐷


− 1)𝑦𝑝 = 𝑠𝑒𝑛(𝑥) + 𝑐𝑜𝑠(2𝑥)

(𝐷 − 1)(𝐴𝑠(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐶𝑠𝑒𝑛(2𝑥) + 𝐷𝑐𝑜𝑠(2𝑥)) = 𝑠(𝑥) + 𝑐𝑜𝑠(2𝑥)


(𝐴𝑠𝑒(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐶𝑠𝑒𝑛(2𝑥) + 𝐷𝑐𝑜𝑠(2𝑥)) − 𝐴𝑠𝑒𝑛(𝑥) − 𝐵𝑐𝑜𝑠(𝑥) →

→ −𝐶𝑠(2𝑥) − 𝐷𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(𝑥) + 𝑐𝑜𝑠(2𝑥)

→ = 𝐴𝑐(𝑥) − 𝐵𝑠𝑒𝑛(𝑥) + 2𝐶𝑐𝑜𝑠(𝑥) − 2𝐷𝑠𝑒𝑛(𝑥)

(𝐴𝑠𝑒(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐶𝑠𝑒𝑛(2𝑥) + 𝐷𝑐𝑜𝑠(2𝑥)) − 𝐴𝑠𝑒𝑛(𝑥) − 𝐵𝑐𝑜𝑠(𝑥) →

→ −𝐶𝑠(2𝑥) − 𝐷𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(𝑥) + 𝑐𝑜𝑠(2𝑥)

𝐴𝑐(𝑥) − 𝐵𝑠𝑒𝑛(𝑥) + 2𝐶𝑐𝑜𝑠(𝑥) − 2𝐷𝑠𝑒𝑛(𝑥) − 𝐴𝑠𝑒𝑛(𝑥) − 𝐵𝑐𝑜𝑠(𝑥) →


→ −𝐶𝑠(2𝑥) − 𝐷𝑐𝑜𝑠(2𝑥) = 𝑠𝑒𝑛(𝑥) + 𝑐𝑜𝑠(2𝑥)

(−𝐴 − 𝐵)𝑠(𝑥) + (2𝐶 − 𝐷)𝑐𝑜𝑠(2𝑥) + (𝐴 − 𝐵)𝑐𝑜𝑠(𝑥) + (−2𝐷 − 𝐶)𝑠𝑒𝑛(2𝑥) →


→ = 𝑠(𝑥) + 𝑐𝑜𝑠(2𝑥)
−𝐴 − 𝐵 = 1
2𝐶 − 𝐷 = 1
𝐴−𝐵 =0
−2𝐷 − 𝐶 = 0

𝐴−𝐵 =0
−𝐴 − 𝐵 = 1
−2𝐵 = 1
1
𝐵=−
2
𝐴−𝐵 =0
𝐴=𝐵
1
𝐴=−
2

2𝐶 − 𝐷 = 1
(2)(−𝐶 − 2𝐷 = 0)

2𝐶 − 𝐷 = 1
−2𝐶 − 4𝐷 = 0
−5𝐷 = 1
1
𝐷=−
5
−2𝐷 − 𝐶 = 0
−2𝐷 = 𝐶
1
−2 (− ) =
𝐶5
2
=𝐶
5
2
𝐶=
5

𝑦𝑝 = 𝐴𝑠(𝑥) + 𝐵𝑐𝑜𝑠(𝑥) + 𝐶𝑠𝑒𝑛(2𝑥) + 𝐷𝑐𝑜𝑠(2𝑥)

1 1 2 1
𝑦𝑝 = − 2 𝑠 (𝑥) − 2 𝑐𝑜𝑠(𝑥) + 5 𝑠𝑒𝑛(2𝑥) − 5 𝑐𝑜𝑠(2𝑥)

1 1 2 1
𝑦𝐺1= 𝑐 𝑒 𝑥 −𝑠 (𝑥) −𝑐𝑜𝑠(𝑥) +𝑠𝑒𝑛(2𝑥) −𝑐𝑜𝑠(2𝑥)
2 2 5 5

10) (𝐷3 − 3𝐷2 + 3𝐷 − 1) = 𝑒𝑥 + 1


(𝐷3 − 3𝐷2 + 3𝐷 − 1)𝑦 = 0
𝑚3 − 3𝑚2 + 3𝑚 − 1 = 0
𝐷1 = ±1
𝑚3 𝑚2 𝑚 𝑇. 𝐼
1 −3 3 −1 𝑚 = 1 ← 𝐼𝑔𝑢𝑎𝑙𝑎𝑟 𝑎 0
1 −2 1 𝑚−1=0
1 −2 1 0

(𝑚 − 1)(𝑚2 − 2𝑚 + 1) = 0
(𝑚 − 1)(𝑚 − 1)(𝑚 − 1) =

0 (𝑚 − 1)3 = 0

𝑚1 − 1 = 0 𝑚2 − 1 = 0 𝑚3 − 1 = 0
𝑚1 = 1 𝑚2 = 1 𝑚3 = 1

𝑦𝑐 = 𝑐1𝑒𝑥 + 𝑐2𝑥𝑒𝑥 + 𝑐3𝑥2𝑒𝑥

𝑦𝑝 = 𝐴𝑒𝑥 + 𝐵
𝑦𝑝 = (𝐴𝑒𝑥)3 + 𝐵

𝑦𝑝 = 𝐴𝑥3𝑒𝑥 + 𝐵

(𝐷3 − 3𝐷2 + 3𝐷 − 1)𝑦 = 𝑒𝑥 + 1


(𝐷3 − 3𝐷2 + 3𝐷 − 1) = 𝑒𝑥 + 1

(𝐷3 − 3𝐷2 + 3𝐷 − 1)(𝐴𝑥3𝑒𝑥 + 𝐵) = 𝑒𝑥 + 1


𝐷3(𝐴𝑥3𝑒𝑥 + 𝐵) − 3𝐷2(𝐴𝑥3𝑒𝑥 + 𝐵) + 3𝐷(𝐴𝑥3𝑒𝑥 + 𝐵) − 𝐴𝑥3𝑒𝑥 − 𝐵 = 𝑒𝑥 + 1
= 𝐴𝑥3𝑒𝑥 + 9𝐴𝑥2𝑒𝑥 + 18𝐴𝑥𝑒𝑥 + 6𝐴𝑒𝑥
= 𝐴𝑥3𝑒𝑥 + 6𝐴𝑥2𝑒𝑥 + 6𝐴𝑥𝑒𝑥
= 𝐴𝑥3𝑒𝑥 + 3𝐴𝑥2𝑒𝑥
𝐷3(𝐴𝑥3𝑒𝑥 + 𝐵) − 3𝐷2(𝐴𝑥3𝑒𝑥 + 𝐵) + 3𝐷(𝐴𝑥3𝑒𝑥 + 𝐵) − 𝐴𝑥3𝑒𝑥 − 𝐵 = 𝑒𝑥 + 1
𝐴𝑥3𝑒𝑥 + 9𝐴𝑥2𝑒𝑥 + 18𝐴𝑥𝑒𝑥 + 6𝐴𝑒𝑥 − 3(𝐴𝑥3𝑒𝑥 + 6𝐴𝑥2𝑒𝑥 + 6𝐴𝑥𝑒𝑥) →
→ +3(𝐴𝑥3𝑒𝑥 + 3𝐴𝑥2𝑒𝑥) − 𝐴𝑥3𝑒𝑥 − 𝐵 = 𝑒𝑥 + 1

𝐴𝑥3𝑒𝑥 + 9𝐴𝑥2𝑒𝑥 + 18𝐴𝑥𝑒𝑥 + 6𝐴𝑒𝑥 − 3𝐴𝑥3𝑒𝑥− 18𝐴𝑥2𝑒𝑥 − 18𝐴𝑥𝑒𝑥 →


→ +3𝐴𝑥3𝑒𝑥 + 9𝐴𝑥2𝑒𝑥 − 𝐴𝑥3𝑒𝑥 − 𝐵 = 𝑒𝑥 + 1

6𝐴𝑒𝑥 − 𝐵 = 𝑒𝑥 + 1
(6𝐴) − 𝐵 = 𝑒𝑥 + 1
6𝐴 = 1 6𝐴 = 1
1
(−1)(−𝐵 = 1) 𝐴=
6
B=-1

𝑦𝑝 = 𝐴𝑥3𝑒𝑥 + 𝐵

1
𝑦𝑝 =𝑥3𝑒𝑥
6 −1

1
𝑦𝐺1= 𝑐 𝑒 𝑥 + 𝑐2 𝑥𝑒 𝑥 + 𝑐3 𝑥 2 𝑒𝑥 +𝑥 𝑒3 −
𝑥
1
6

11) (𝐷3 − 2𝐷2 + 5𝐷) = 10 + 15𝑐𝑜(2𝑥)


(𝐷3 − 2𝐷2 + 5𝐷)𝑦 = 0
𝑚3 − 2𝑚2 + 5𝑚 = 0
(𝑚2 − 2𝑚 + 5) = 0

−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −2
𝑐=5

𝑚 = −(−2) ± √(−2)2 − 4(1)(5)


2(1)

𝑚 = 2 ± √−16
2

𝑚 = 2 ± √16(−1)
2
√𝑎𝑏 = √𝑎 ∙ √𝑏
2 ± √16 ∙ √−1
𝑚=
2

𝑖 = √−1
2 ± 4𝑖
𝑚=
2
𝑚 = 1 ± 2𝑖
𝑚1 = 0 𝑚2 = 1 + 2𝑖 𝑚3 = 1 − 2𝑖

𝑦 = 𝑐1𝑒0𝑥 + (𝑐2𝑠𝑒𝑛(2𝑥) + 𝑐3𝑐𝑜𝑠(2𝑥))

𝑦 = 𝑐1𝑒0 + 𝑐2𝑒𝑥𝑠(2𝑥) + 𝑐3𝑒𝑥𝑐𝑜𝑠(2𝑥)


𝑎0 = 1
𝑦 = 𝑐1(1) + 𝑐2𝑒𝑥𝑠𝑒𝑛(2𝑥) + 𝑐3𝑒𝑥𝑐𝑜𝑠(2𝑥)
𝑦 = 𝑐1 + 𝑐2𝑒𝑥𝑠(2𝑥) + 𝑐3𝑒𝑥𝑐𝑜𝑠(2𝑥)

𝑦𝑝 = 𝐴 + 𝐵𝑠(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)
𝑦𝑝 = (𝑥) + 𝐵𝑠𝑒(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)

𝑦𝑝 = 𝐴𝑥 + 𝐵𝑠(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)

(𝐷3 − 2𝐷2 + 5𝐷)𝑦 = 10 + 15𝑐(2𝑥) (𝐷3

− 2𝐷2 + 5𝐷)𝑦𝑝 = 10 + 15𝑐𝑜𝑠(2𝑥)

(𝐷3 − 2𝐷2 + 5𝐷)(𝐴𝑥 + 𝐵𝑠(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) = 10 + 15𝑐(2𝑥)

𝐷3(𝐴𝑥 + 𝐵𝑠𝑒𝑛(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) − 2𝐷2(𝐴𝑥 + 𝐵𝑠𝑒𝑛(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) →

→ +5(𝐴𝑥 + 𝐵𝑠𝑒(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) = 10 + 15𝑐𝑜𝑠(2𝑥)

→ −8𝐵𝑐(2𝑥) + 8𝐶𝑠𝑒𝑛(2𝑥)

→ −4𝐵𝑠(2𝑥) − 4𝐶𝑐𝑜𝑠(2𝑥)

→ 𝐴 + 2𝐵𝑐(2𝑥) − 2𝐶𝑠𝑒𝑛(2𝑥)

𝐷3(𝐴𝑥 + 𝐵𝑠𝑒𝑛(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) − 2𝐷2(𝐴𝑥 + 𝐵𝑠𝑒𝑛(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) →

→ +5(𝐴𝑥 + 𝐵𝑠𝑒(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)) = 10 + 15𝑐𝑜𝑠(2𝑥)


−8𝐵𝑐(2𝑥) + 8𝐶𝑠𝑒𝑛(2𝑥) − 2(−4𝐵𝑠𝑒𝑛(2𝑥) − 4𝐶𝑐𝑜𝑠(2𝑥)) →

→ +5(𝐴 + 2𝐵𝑐(2𝑥) − 2𝐶𝑠𝑒𝑛(2𝑥)) = 10 + 15𝑐𝑜𝑠(2𝑥)

−8𝐵𝑐(2𝑥) + 8𝐶𝑠𝑒𝑛(2𝑥) + 8𝐵𝑠𝑒𝑛(2𝑥) + 8𝐶𝑐𝑜𝑠(2𝑥) + 5𝐴 + 10𝐵𝑐𝑜𝑠(2𝑥) →


→ −10𝐶𝑠(2𝑥) = 10 + 15𝑐𝑜𝑠(2𝑥)

2𝐵𝑐𝑜𝑠(2𝑥) + 8𝐶𝑐𝑜𝑠(2𝑥) − 2𝐶𝑠𝑒𝑛(2𝑥) + 8𝐵𝑠𝑒𝑛(2𝑥) + 5𝐴 = 10 + 15𝑐𝑜𝑠(2𝑥)


(2𝐵 + 8𝐶)𝑐𝑜𝑠(2𝑥) + (8𝐵 − 2𝐶)𝑠𝑒𝑛(2𝑥) + 5𝐴 = 10 + 15𝑐𝑜𝑠(2𝑥)
2𝐵 + 8𝐶 = 15 5𝐴 = 10
10
8𝐵 − 2𝐶 = 0 𝐴=
5
5𝐴 = 10
A=2
*Utilizando un sistema de ecuaciones por el método de suma y resta para
encontrar los valores de B y C
2𝐵 + 8𝐶 = 15
(4)(8𝐵 − 2𝐶 = 0)
2𝐵 + 8𝐶 = 15
32𝐵 − 8𝐶 = 0
34𝐵 = 15
15
𝐵=
34
8𝐵 − 2𝐶 = 0
8𝐵 = 2𝐶
2𝐶 = 8𝐵
15
2𝐶 = 8 ( )
34
120
2𝐶 =
34
60
2𝐶 =
17
60
𝐶=
17(2)
60
𝐶=
34
*Sustituir el valor de A, B y C en la ecuación de 𝑦𝑝

𝑦𝑝 = 𝐴𝑥 + 𝐵𝑠(2𝑥) + 𝐶𝑐𝑜𝑠(2𝑥)
15 60
𝑦𝑝 = 2𝑥 + 𝑠(2𝑥) + 𝑐𝑜𝑠(2𝑥)
34 34
*Extraer factor común
1
𝑦𝑝 = 2𝑥 + () (15𝑠 (2𝑥) + 60𝑐𝑜𝑠(2𝑥)) 𝑺𝒐𝒍𝒖𝒄𝒊ó𝒏 𝒑𝒂𝒓𝒕𝒊𝒄𝒖𝒍𝒂𝒓
34

*Sustituyendo los valores de 𝑦𝑐 y 𝑦𝑝 para encontrar la solución general


1
𝑦𝐺 = 𝑐1 + 𝑐2𝑒𝑥𝑠 (2𝑥) + 𝑐3𝑒𝑥𝑐𝑜𝑠(2𝑥) + 2𝑥 + () (15𝑠𝑒𝑛(2𝑥) + 60𝑐𝑜𝑠(2𝑥))
34
𝑺𝒐𝒍𝒖𝒄𝒊ó𝒏 𝒈𝒆𝒏𝒆𝒓𝒂𝒍

12) (𝐷2 − 2𝐷 + 2) = 𝑒𝑥𝑠𝑒(𝑥)


*Resolviendo la ecuación como homogénea para encontrar 𝑦𝑐
(𝐷2 − 2𝐷 + 2)𝑦 = 0
*Reescribiendo la ecuación reemplazando la “D” por “m”. La “y” no es necesaria
escribirla
𝑚2 − 2𝑚 + 2 = 0
*Factorizar la ecuación
*Utilizando la formula general
−𝑏 ± √𝑏2 − 4𝑎𝑐
𝑥=
2𝑎
𝑎=1
𝑏 = −2
𝑐=2
−(−2) ± √(−2)2 − 4(1)(2)
𝑚=
2(1)

2 ± √−4
𝑚=
2
2 ± √4(−1)
𝑚=
2
*Aplicando reglas de los radicales

√𝑎𝑏 = √𝑎 ∙ √𝑏
2 ± √4 ∙ √−1
𝑚=
2
*Aplicando propiedades de los números complejos

𝑖 = √−1
2 ± 2𝑖
𝑚=
2
𝑚 =1±𝑖
*Encontrando el valor de las raíces “m”

𝑚1 = 1 + 𝑖 𝑚2 = 1 − 𝑖

*Sustituyendo los valores de “m”


*Utilizando fórmulas para raíces con números complejos
𝑦 = (𝑐1𝑠𝑒𝑛𝑥 + 𝑐2𝑐𝑜𝑠𝑥)

𝑦 = 𝑐1𝑒𝑥𝑠𝑒𝑛𝑥 + 𝑐2𝑒𝑥𝑐𝑜𝑠𝑥 𝑺𝒐𝒍𝒖𝒄𝒊ó𝒏 𝒉𝒐𝒎𝒐𝒈é𝒏𝒆𝒂

*Verificar si alguna expresión de la solución homogénea aparece en el resultado


de nuestra ecuación original
*Dado a que, si hay términos semejantes en la respuesta de la homogénea y en
el resultado de la ecuación original, la solución particular 𝑦𝑝 se multiplicará por una
“x” a la mínima potencia, de manera que la solución particular no repita ningún
termino.
*Utilizando la tabla de casos para determinar el valor de 𝑦𝑝

𝑦𝑝 = (𝐴𝑠𝑒𝑛(𝑥) + 𝐵𝑐𝑜𝑠(𝑥))𝑒𝑥
*Multiplicaremos 𝑦𝑝 por 𝑥, ya que así se evita que se repitan términos en
comparación con la solución homogénea

𝑦𝑝 = ((𝐴𝑠𝑒𝑛(𝑥) + 𝐵𝑐𝑜𝑠(𝑥))𝑒𝑥) 𝑥

𝑦𝑝 = (𝐴𝑠𝑒𝑛(𝑥) + 𝐵𝑐𝑜𝑠(𝑥))𝑥𝑒𝑥

𝑦𝑝 = 𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)

*Sustituir 𝑦𝑝 en “y” de la ecuación diferencial original

(𝐷2 − 2𝐷 + 2)𝑦 = 𝑒𝑥𝑠(𝑥) (𝐷2

− 2𝐷 + 2)𝑦𝑝 = 𝑒𝑥𝑠𝑒𝑛(𝑥)

(𝐷2 − 2𝐷 + 2)(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) = 𝑒𝑥𝑠𝑒𝑛(𝑥)

𝐷2(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) − 2𝐷(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) →

→ +2(𝐴𝑥𝑒𝑥𝑠(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) = 𝑒𝑥𝑠𝑒𝑛(𝑥)

*Derivar las funciones que tengan un diferencial “D”, según su potencia a la que
estén elevados, será las veces en que la función será derivada

∗ 𝐷𝑒𝑟𝑖𝑣𝑎𝑛𝑑𝑜 2 𝑣𝑒𝑐𝑒𝑠 (𝐴𝑥𝑒𝑥𝑠(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) 𝑝𝑎𝑟𝑎 𝐷2 𝑜 𝑦′′ →

→ 𝐴 (𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑥(𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝑒𝑥𝑠𝑒𝑛(𝑥) − 𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑒𝑥𝑐𝑜𝑠(𝑥))) →

→ +𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝐵(−𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑒𝑥𝑐𝑜𝑠(𝑥) →

→ 𝑥(−𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑒𝑥𝑐𝑜𝑠(𝑥) − 𝑒𝑥𝑐𝑜𝑠(𝑥) − 𝑒𝑥𝑠𝑒𝑛(𝑥)) + (𝑒𝑥𝑐𝑜𝑠(𝑥) − 𝑒𝑥𝑠𝑒𝑛(𝑥))

*Reduciendo términos

(2𝑒𝑥𝑐𝑜(𝑥) + 2𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) →

→ +(2𝑒𝑥𝑐𝑜𝑠(𝑥) − 2𝑒𝑥𝑠𝑒𝑛(𝑥) − 2𝑥𝑒𝑥𝑠𝑒𝑛(𝑥))


*Realizando operaciones
2𝐴𝑒𝑥𝑐(𝑥) + 2𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + 2𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) − 2𝐵𝑒𝑥𝑠𝑒𝑛(𝑥) →
→ −2𝐵𝑥𝑒𝑥𝑠(𝑥)

∗ 𝐷𝑒𝑟𝑖𝑣𝑎𝑛𝑑𝑜 1 𝑣𝑒𝑧 (𝐴𝑥𝑒𝑥𝑠(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) 𝑝𝑎𝑟𝑎 𝐷 𝑜 𝑦′ →

→ (𝐴𝑒𝑥 + 𝐴𝑥𝑒𝑥)𝑠𝑒𝑛(𝑥) + 𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + (𝐵𝑒𝑥 + 𝐵𝑥𝑒𝑥)𝑐𝑜𝑠(𝑥) − 𝐵𝑥𝑒𝑥𝑠𝑒𝑛(𝑥)

*Extraer factor común

𝐴 (𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑥(𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝑒𝑥𝑐𝑜𝑠(𝑥))) + 𝐵 (𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝑥(𝑒𝑥𝑐𝑜𝑠(𝑥) − 𝑒𝑥𝑠𝑒𝑛(𝑥)))

*Realizando operaciones
𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) →
→ −𝐵𝑥𝑒𝑥𝑠𝑒𝑛(𝑥)

*Sustituyendo los valores de las derivadas en la ecuación

𝐷2(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) − 2𝐷(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) →

→ +2(𝐴𝑥𝑒𝑥𝑠(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) = 𝑒𝑥𝑠𝑒𝑛(𝑥)

2𝐴𝑒𝑥𝑐(𝑥) + 2𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + 2𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) − 2𝐵𝑒𝑥𝑠𝑒𝑛(𝑥) →


→ −2𝐵𝑥𝑒𝑥𝑠(𝑥) − 2(𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + 𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) →

→ +𝐵𝑥𝑒𝑥𝑐(𝑥) − 𝐵𝑥𝑒𝑥𝑠𝑒𝑛(𝑥)) + 2(𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)) = 𝑒𝑥𝑠𝑒𝑛(𝑥)

2𝐴𝑒𝑥𝑐(𝑥) + 2𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) + 2𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) − 2𝐵𝑒𝑥𝑠𝑒𝑛(𝑥) →


→ −2𝐵𝑥𝑒𝑥𝑠(𝑥) − 2𝐴𝑒𝑥𝑠𝑒𝑛(𝑥) − 2𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) − 2𝐴𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) − 2𝐵𝑒𝑥𝑐𝑜𝑠(𝑥) →
→ −2𝐵𝑥𝑒𝑥𝑐(𝑥) + 2𝐵𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 2𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) = 𝑒𝑥𝑠𝑒𝑛(𝑥)

2𝐴𝑒𝑥𝑐(𝑥) − 2𝐵𝑒𝑥𝑠𝑒𝑛(𝑥) = 𝑒𝑥𝑠𝑒𝑛(𝑥)


(2𝐴)𝑒𝑥𝑐(𝑥) + (−2𝐵)𝑒𝑥𝑠𝑒𝑛(𝑥) = 𝑒𝑥𝑠𝑒𝑛(𝑥)
2𝐴 = 0 2𝐴 = 0 − 2𝐵 = 1
0 1
−2𝐵 = 1 𝐴= 𝐵=−
2 2
𝐴=0

*Sustituir el valor de A y B en la ecuación de 𝑦𝑝

𝑦𝑝 = 𝐴𝑥𝑒𝑥𝑠𝑒𝑛(𝑥) + 𝐵𝑥𝑒𝑥𝑐𝑜𝑠(𝑥)
1
𝑦𝑝 = 0𝑥𝑒 𝑥𝑠𝑒𝑛 (𝑥) − 𝑥𝑒 𝑥𝑐𝑜𝑠 (𝑥)
2
1
𝑦𝑝 = −𝑥𝑒𝑥𝑐𝑜𝑠(𝑥) 𝑺𝒐𝒍𝒖𝒄𝒊ó𝒏 𝒑𝒂𝒓𝒕𝒊𝒄𝒖𝒍𝒂𝒓
2

*Sustituyendo los valores de 𝑦𝑐 y 𝑦𝑝 para encontrar la solución general

1 𝑥
𝑦𝐺1= 𝑐 𝑒 𝑥 𝑠𝑒𝑛𝑥 + 𝑐2 𝑒 𝑥 𝑐𝑜𝑠𝑥 −𝑥𝑒 𝑐𝑜𝑠(𝑥) 𝑺𝒐𝒍𝒖𝒄𝒊ó𝒏 𝒈𝒆𝒏𝒆𝒓𝒂𝒍
2

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