Serbian C1
Serbian C1
practice problems
Contents 1
0 Review 2
1 Sets 4
2 Inequalities 5
4 Functions 7
7 Composition of functions 10
9 Limit of sequences 12
10 Limits of functions 13
11 Continuous functions 15
12 Derivatives 16
13 Analysis of functions 19
14 Integrals 21
1
0 Review
1. What is the 2007-th digit after the decimal point in the decimal representation of the
1
number ?
7
(a) 𝑥2 − 7𝑥 + 12 (b) 𝑥2 + 𝑥 − 6
(c) 𝑥2 + 8𝑥 + 16 (d) 9𝑥2 + 9𝑥 + 2
(e) 9𝑥2 − 6𝑥 + 1 (f) 5𝑥2 − 5
(g) 3𝑥2 − 18𝑥 + 27 (h) 2𝑥2 − 12𝑥 + 16
2
where 𝑎, 𝑏, 𝑐 are constants and 𝑎 ≠ 𝑏.
9. Find the value(s) for 𝑘 so that the equation 𝑥2 + 𝑘𝑥 + (𝑘 + 3) = 0 has only one
solution.
10. Find the positive number so that the sum of that number and its square is 210.
3
1 Sets
1. Given the sets 𝐴 = {𝑥 ∈ 𝑅 ∶ 𝑥 > 0} and 𝐵 = {𝑦 ∈ 𝑅 ∶ 𝑦 > 0}, are 𝐴 and 𝐵 the same
sets?
3. Let 𝐴, 𝐵, and 𝐶 be subsets of a universal set 𝑈. For each of the following equalities
determine whether it is true or not.
(a) 𝐴 − 𝐵 = 𝐴 ∩ 𝐵 (b) (𝐴 ∪ 𝐵) ∩ 𝐶 = 𝐴 ∪ (𝐵 ∩ 𝐶)
(c) (𝐴 ∪ 𝐵) ∩ 𝐵 = 𝐵 − 𝐴
5. Given the sets 𝐴 = [1, 5], 𝐵 = [3, 9), 𝐶 = {1, 5}, and 𝐷 = [5, ∞), find the following
sets.
6. Let 𝐴 and 𝐵 be intervals on the real line. Is it always the case that 𝐴 ∩ 𝐵 is an
interval too? What about 𝐴 ∪ 𝐵 being an interval?
4
2 Inequalities
5
3 Straight line equations
1. Find the equations of the following lines in explicit (slope-intercept) and general
forms.
(a) Line passes through the origin and the point (−2, 3).
(b) Line’s slope is 2 and passes through the point (5, −1).
(c) Line’s slope is −3 and its 𝑦-intercept is (0, 7).
(d) Line passes through the point (−3, 2) and it is parallel to the line 2𝑥 − 𝑦 − 3 = 0.
(e) Line passes through the point (1, 4) and it is perpendicular to the line 𝑥+3𝑦 = 0.
(f) Line passes through the point (1, −1) and it is perpendicular to the 𝑦-axes.
2. Let ℓ1 and ℓ2 be two lines such that ℓ1 passes through the points 𝐴(1, 3) and 𝐵(2, 5),
while ℓ2 passes through the point 𝐶(0, 2) and its slope is − 23 .
(a) Find the equations of the line ℓ1 in explicit (slope-intercept) and general forms.
(b) Find the equations of the line ℓ2 in explicit (slope-intercept) and general forms.
(c) Find the coordinates of the point of intersection of the lines ℓ1 and ℓ2 .
3. For any real number 𝑎, let ℓ𝑎 be the line given by the equation 𝑦 = 𝑎𝑥 + 𝑎2 .
6
4 Functions
𝑥−5
1. Given the function 𝑓(𝑥) = , calculate the following expressions.
𝑥2 + 4
𝑥 √
2. Given the functions 𝑓(𝑥) = and 𝑔(𝑥) = 𝑥 − 1, calculate the following expres-
𝑥+1
sions.
𝑓(3)
(a) 𝑓(1) + 𝑔(1) (b) 𝑓(2)𝑔(2) (c)
𝑔(3)
(d) 𝑓(𝑎 − 1) + 𝑔(𝑎 + 1) (e) 𝑓(𝑎2 + 1)𝑔(𝑎2 + 1) (f) 𝑓(1)𝑔2 (3)
3. Given the function 𝑓(𝑥) = 𝑥2 −3𝑥+4, calculate and simplify the following expressions.
𝑓(1 + ℎ) − 𝑓(1) 𝑓(𝑎 + ℎ) − 𝑓(𝑎)
(a) 𝑓(𝑎 + 𝑏) (b) (c)
ℎ ℎ
4. Given the function 𝑓(𝑥) satisfying 𝑓 (2𝑥 + 3) = 𝑥2 for all real numbers 𝑥, calculate
the following expressions.
7
5 Domains and ranges of functions
3. Given the function 𝑓(𝑥) satisfying 𝑓(2𝑥 + 3) = 𝑥2 for all real numbers 𝑥, find its
domain and range.
1
4. Given the function 𝑓(𝑥) satisfying 𝑓( ) = 2𝑥 − 12 for all real numbers 𝑥, find its
𝑥+1
domain and range.
5. For each of the following functions find its domain and range.
8
6 Graphs of elementary functions
3
1. Consider the functions 𝑓(𝑥) = −2𝑥2 + 4𝑥 − and 𝑔(𝑥) = 2𝑥 − 1.
2
(a) Sketch the graphs of 𝑓(𝑥) and 𝑔(𝑥) on the same diagram of the Cartesian plane.
(b) Find the coordinates of the point(s) where the graph of 𝑓(𝑥) intersects the 𝑥-axes
and 𝑦-axes, as well as the coordinates of the vertex point of the graph of 𝑓(𝑥).
(c) Find the coordinates of the point(s) of intersection of the graphs of 𝑓(𝑥) and
𝑔(𝑥).
1
2. Consider the functions 𝑓(𝑥) = 𝑚𝑥 + 𝑛 and 𝑔(𝑥) = .
𝑥
(a) For what values of 𝑚 and 𝑛 does the graph of 𝑓(𝑥) pass through the point (−1, 1)
and intersect the graph of 𝑔(𝑥) in exactly one point?
(b) For what values of 𝑚 and 𝑛 does the graph of 𝑓(𝑥) not intersect the graph of
𝑔(𝑥) at all?
9
7 Composition of functions
1. Given the following functions 𝑓(𝑥) = 𝑥2 + 1 and 𝑔(𝑥) = 𝑥 + 1, calculate the following
expressions.
2. Specify the functions 𝑓(𝑥) and 𝑔(𝑥) so that 𝑔(𝑥) has the form 𝑥𝑟 with 𝑟 ≠ 1, and the
composition (𝑔 ∘ 𝑓)(𝑥) is equal to the following expressions.
√ 1
(a) 𝑥2 + 1 (b)
𝑥+1
10
8 Injective and inverse functions
11
9 Limit of sequences
2. Suppose $50,000 is deposited in a bank account and the annual interest rate is 2%.
(a) What amount will the account have after one year if the interest is compounded
quarterly and what if it is compounded monthly?
(b) If the interest is compounded 𝑛 times a year, express the amount 𝐴𝑛 after one
year in terms of 𝑛.
(c) Does lim 𝐴𝑛 exist?
𝑛→∞
12
10 Limits of functions
2. The concentration 𝐶 of a drug in the patient’s bloodstream 𝑡 hours after it was in-
jected is given by the function
0.15𝑡
𝐶(𝑡) = .
𝑡2 + 3
𝑥3 𝑥
𝑥→0− 𝑥→0− 𝑥→0+
(g) lim (2 − 3 )
1
𝑥
𝑥→0−
(a) lim (2𝑥 + 5) (b) lim (𝑥2 + 3𝑥 − 4) (c) lim (𝑥2 − 5𝑥 − 8)3
𝑥→−7 𝑥→2 𝑥→7
√
3𝑥 − 5 2 𝑥 𝑥2 + 1
(d) lim (𝑥 + 3) 2007
(e) lim ( ) (f) lim
𝑥→−4 𝑥→0 2𝑥 + 7 𝑥→1 𝑥+1
13
𝑥2 − 4 𝑥2 − 4
(g) lim 25+4𝑥 (h) lim (i) lim
𝑥→−2 𝑥→−2 𝑥2+𝑥−2 𝑥→−2 𝑥2−𝑥+2
𝑥2 − 6𝑥 𝑥2 + 25 𝑥−3
(j) lim 2 (k) lim (l) lim 2
𝑥→6 𝑥 − 5𝑥 − 6 𝑥→5 𝑥 − 5 𝑥→3 𝑥 + 9
√
𝑥2 + 𝑥 − 2 𝑥2 + 𝑥 − 2 𝑥−2
(m) lim 2
(n) lim 2
(o) lim
𝑥→1 𝑥 − 1 𝑥→−1 𝑥 − 1 𝑥→4 𝑥 − 4
√ 1 1
𝑥−5 𝑥−3 −
(p) lim √ (q) lim (r) lim 𝑥 2
.
𝑥→2 2 − 𝑥 − 1 𝑥→9 𝑥 − 9 𝑥→2 𝑥 − 2
1 1
√ − √
𝜋
(s) lim (t) lim sin( )
𝑥 2
𝑥→2 𝑥−2 𝑥→0 𝑥
𝑓(𝑥 + ℎ) − 𝑓(𝑥)
5. For each of the following functions find lim .
ℎ→0 ℎ
14
11 Continuous functions
⎧ 𝑥2 ,𝑥<1
{
1. Given the function 𝑓(𝑥) = 1 ,1≤𝑥<2 ,
⎨1
{ ,𝑥≥2
⎩𝑥
𝑥2 + 𝑥 − 2
2. Given the function 𝑓(𝑥) = √ ,
1− 𝑥
1
3. Given the function 𝑓(𝑥) = sin ,
𝑥
3𝑥 + 2 ,𝑥<2
𝑓(𝑥) = {
𝑥2 + 𝑘 ,𝑥≥2
15
12 Derivatives
1. For each of the following functions 𝑓(𝑥) find its derivative 𝑓 ′ (𝑥) by definition.
3. For each of the following functions 𝑓(𝑥) find 𝑓 ′ (𝑎) for given 𝑎.
2 4
(a) 𝑓(𝑥) = 𝑥3 − 4𝑥, 𝑎 = 1 (b) 𝑓(𝑥) = + , 𝑎=2
𝑥3𝑥
√
(c) 𝑓(𝑥) = 3𝑥 3 − 5𝑥 3 , (d) 𝑓(𝑥) = 𝜋𝑥 − 2 𝑥, 𝑎 = 4
1 2
2
𝑎 = 27
𝑥2 + 1
(e) 𝑓(𝑥) = (𝑥2 + 3)(𝑥3 + 2), 𝑎=1 (f) 𝑓(𝑥) = , 𝑎=2
2𝑥 − 3
𝑥2 + 3𝑥 − 5
(g) 𝑓(𝑥) = , 𝑎=1
𝑥2 − 7𝑥 + 5
(a) Find the slope of 𝑓(𝑥) at the point with 𝑥-coordinate equal to 2.
(b) Find the tangent line of 𝑓(𝑥) at the point (1, −1).
(c) Find the point(s) on the graph of the function where the tangent line of 𝑓(𝑥) is
horizontal.
16
(a) 𝑦 = 5 cos 𝑥 − 2𝑥 (b) 𝑦 = 1 − 2 tan 𝑥
(c) 𝑦 = sin 𝑥 − 𝑥 2
(d) 𝑦 = 𝑥2 sin 𝑥
1
(e) 𝑦 = cos2 𝑥 (f) 𝑦 =
cos 𝑥
cos 𝑥
(g) 𝑦 = sin 𝑥 ⋅ cos 𝑥 (h) 𝑦 =
𝑥3 + 1
(i) 𝑦 = (𝑥 + cos 𝑥)2 (j) 𝑦 = (sin 𝑥 + cos 𝑥)2
8. For each of the following functions 𝑓(𝑥) find 𝑓 ′ (𝑎) for given 𝑎.
ln 𝑥
(a) 𝑓(𝑥) = 𝑒𝑥 tan 𝑥, 𝑎=0 (b) 𝑓(𝑥) = , 𝑎=1
𝑥2 + 1
17
10. For each of the following functions 𝑦 = 𝑓(𝑥) find 𝑦′ .
√
(a) 𝑦 = (2𝑥3 + 5𝑥2 )6 (b) 𝑦 = 9 + 4𝑥
√
4𝑥2 + 5
(c) 𝑦 = (d) 𝑦 = cos 5𝑥
3
(e) 𝑦 = sin(6𝑥 − 7) (f) 𝑦 = sin4 𝑥
(g) 𝑦 = cos5 (6𝑥 − 7) (h) 𝑦 = 4𝑥 sin 3𝑥
tan 𝑥
(i) 𝑦 = tan(8𝑥3 + 1) (j) 𝑦 =
𝑥+2
(k) 𝑦 = 2𝑒3𝑥 + 4𝑥 − 5 (l) 𝑦 = 𝑥 𝑒𝑥
2
𝑥2
(m) 𝑦 = (n) 𝑦 = ln 8𝑥
𝑒𝑥
(o) 𝑦 = ln(5 − 2𝑥) (p) 𝑦 = ln(1 − 𝑥2 )
√
(q) 𝑦 = ln 2𝑥 + 11 (r) 𝑦 = 3𝑥 ln 𝑥
(s) 𝑦 = ln(ln 𝑥) (t) 𝑦 = 𝑒𝑥 ln 𝑥
2
𝑥2 𝑥3 𝑥4 𝑥5 𝑥6
12. Find 𝑓 ′ (𝑥), 𝑓 ″ (𝑥), and 𝑓 (3) (𝑥) if 𝑓(𝑥) = 1 + 𝑥 + + + + + .
2 6 24 120 720
18
13 Analysis of functions
1. For each of the following functions 𝑓(𝑥) find its intervals of monotonicity (i.e., where
the function is increasing and decreasing).
2. For each of the following functions 𝑓(𝑥) find the type of its critical points (i.e., whether
the point is maximum or minimum).
3. For each of the following functions 𝑓(𝑥) find the intervals where the function is convex
and concave.
√
(a) 𝑓(𝑥) = 𝑥 (b) 𝑓(𝑥) = 𝑥3 − 6𝑥2 + 9𝑥
2
(c) 𝑓(𝑥) = 3𝑥5 − 9𝑥4 + 8𝑥3 (d) 𝑓(𝑥) = 𝑥 +
𝑥
4. For each of the following functions 𝑓(𝑥) find its inflection points.
1 1
(a) 𝑓(𝑥) = 2𝑥3 + 9𝑥2 − 108𝑥 + 35 (b) 𝑓(𝑥) = 1 − +
𝑥 𝑥2
5. For each of the following functions 𝑓(𝑥) find its domain, asymptotes, 𝑥- and 𝑦-
intercepts, intervals of monotonicity, intervals of convexity/concavity, and sketch the
graph of the function.
𝑥 1 + 𝑥2
(a) 𝑓(𝑥) = (b) 𝑓(𝑥) =
1 + 𝑥2 1+𝑥
3𝑥(1 − 𝑥) 𝑥3
(c) 𝑓(𝑥) = (d) 𝑓(𝑥) =
1 + 𝑥2 4 − 𝑥2
2𝑥 − 1
(e) 𝑓(𝑥) = (f) 𝑓(𝑥) = √1 + 𝑥2
(𝑥 − 1)2
19
√
(g) 𝑓(𝑥) = 1 − 𝑥2 (h) 𝑓(𝑥) = 𝑥2 𝑒−𝑥
𝑒𝑥 𝑒𝑥 − 𝑒−𝑥
(i) 𝑓(𝑥) = (j) 𝑓(𝑥) =
1 + 𝑒𝑥 2
1+𝑥
(k) 𝑓(𝑥) = ln (1 + 𝑥2 ) (l) 𝑓(𝑥) = ln √
1−𝑥
20
14 Integrals
3
(e) ∫(6𝑥5 − 2𝑥−4 − 7𝑥) 𝑑𝑥 (f) ∫ ( − 5 + 4𝑒𝑥 + 7𝑥 ) 𝑑𝑥
𝑥
1 1 𝑥−2
(g) ∫ ( 2
− 4 ) 𝑑𝑥 (h) ∫ √ 𝑑𝑥
𝑥 𝑥 3𝑥 𝑥
2
𝑥2 + 1 √ 1
(i) ∫ √ 𝑑𝑥 (j) ∫ ( 𝑥 + √ ) 𝑑𝑥
𝑥 𝑥
𝑥4 − 1 𝑥2 + 1
(k) ∫ 𝑑𝑥 (l) ∫ 𝑑𝑥
𝑥2 + 1 𝑥2
tan 𝑥
(o) ∫(cos 𝑥 + 2 sin 𝑥) 𝑑𝑥 (p) ∫ 𝑑𝑥
cos 𝑥
𝑥 sin 𝑥1
(i) ∫ 𝑑𝑥 (j) ∫ 𝑑𝑥
𝑥2 + 1 𝑥2
𝜋+𝑥
(k) ∫ cos (𝑥 + 𝜋3 ) 𝑑𝑥 (l) ∫ sin ( ) 𝑑𝑥
5
sin 2𝑥 sin 2𝑥
(m) ∫ 𝑑𝑥 (n) ∫ 𝑑𝑥
1 + cos2 𝑥 1 + sin 𝑥
𝑥3 + 𝑥
(o) ∫(𝑥 + 1)(𝑥2 + 2𝑥 + 3)7 𝑑𝑥 (p) ∫ 𝑑𝑥
(𝑥4 + 2𝑥2 + 3)11
21
√
𝑒 𝑥
(q) ∫(𝑒 − 3𝑥) (𝑒 − 3) 𝑑𝑥
𝑥 4 𝑥
(r) ∫ √ 𝑑𝑥
𝑥
ln(𝑥 + 1) 1
(s) ∫ 𝑑𝑥 (t) ∫ 𝑑𝑥
𝑥+1 𝑥 ln 𝑥
1
(u) ∫ 𝑑𝑥 (v) ∫(𝑥 + 1)15 𝑑𝑥
2𝑥 + 7
𝑥
(w) ∫ √ 𝑑𝑥 (x) ∫ 𝑥(𝑥 + 1)15 𝑑𝑥
𝑥+1
1
(𝑥2 − 1)𝑒𝑥+ 𝑥
(y) ∫ 𝑑𝑥
𝑥2
ln 𝑥
(e) ∫ ln 𝑥 𝑑𝑥 (f) ∫ 𝑑𝑥
𝑥2
1
𝑒𝑥 1
(g) ∫ 3 𝑑𝑥 (h) ∫ 𝑑𝑥
𝑥 𝑥2 − 7
1 𝑥3
(i) ∫ 𝑑𝑥 (j) ∫ 𝑑𝑥
5 − 4𝑥2 𝑥+3
𝑥−3 𝑥+2
(k) ∫ 3 𝑑𝑥 (l) ∫ 3 𝑑𝑥
𝑥 −𝑥 𝑥 − 2𝑥2
𝑥4 + 2 1
(m) ∫ 𝑑𝑥 (n) ∫ 𝑑𝑥
𝑥2 + 1 𝑥2 − 6𝑥 + 13
22
𝜋
2 2
2
ln 2𝑥
(i) ∫ sin 𝑥(cos 2𝑥) 𝑑𝑥 (j) ∫ 𝑑𝑥
0 1
𝑥
𝑒𝜋 𝑒2
sin(ln 𝑥) 1
(k) ∫ 𝑑𝑥 (l) ∫ 𝑑𝑥
𝑥 𝑥 ln 𝑥
1 𝑒
1 1
(m) ∫ (𝑥 − 1)(𝑥2 − 2𝑥)4 𝑑𝑥 (n) ∫ 𝑥(1 − 𝑥)7 𝑑𝑥
−1 0
8 3
𝑥
(o) ∫ √ 𝑑𝑥 (p) ∫ √𝑥5 + 2 𝑑𝑥
𝑥+1
0 3
−𝑒 3
3
(q) ∫ 𝑑𝑥 (r) ∫ |𝑥2 − 1| 𝑑𝑥
−𝑒2
𝑥 −2
2 2
(s) ∫ (𝑥 − 2|𝑥|) 𝑑𝑥 (t) ∫ (𝑥2 − |𝑥 − 1|) 𝑑𝑥
−1 0
23