MIDDLE EAST TECHNICAL UNIVERSITY
ES202 – Mathematics for Engineers
                                                       Murat Büyük, PhD
                                                           Assignment-1
   1) Let, 𝑎⃗ = (2, −3,4), 𝑏⃗⃗ = (−1,2,5), 𝑐⃗ = (3,6, −1); Find the following:
                                                                                     ⃗⃗
                                                                                 𝑎⃗⃗.𝑏
       i)        𝑎⃗. (𝑎⃗ + 𝑏⃗⃗ + 𝑐⃗) , ii) 𝑎⃗. (4𝑏⃗⃗) , iii) (𝑐⃗. 𝑏⃗⃗) 𝑎⃗ , iv) ( ⃗⃗ ⃗⃗) 𝑏⃗⃗
                                                                                   𝑏.𝑏
   2) For which values of bi does the system have infinitely many solutions?
      x1+3x2+5x3+8x4=b1
      2x1+5x2+14x3+10x4=b2
      x1+3x2+16x3-3x4=b3
      2x1+6x2+20x3+6x4=b4
   3) Find the inverse of the following matrices:
            1 3       4          2 4     1
      𝐴 = [3 11 18], 𝐵 = [6 6 −20]
            2 6 11               1 5 12
   4) Find det[A], det[B]:
            4 1 3          0          3 2 11 7
            8 1 12 5                  1 −2 2 4
      𝐴=[                    ], 𝐵 = [          ]
            −8 3 −8 28                2 0  7 8
            4 4 6 26                  1 −6 0 9
   5) Evaluate, (|𝑢         ⃗⃗⃗ and (𝑣⃗x𝑤
                    ⃗⃗|𝑣⃗). 𝑤           ⃗⃗⃗) + 2𝑢
                                                ⃗⃗ , where:
      ⃗⃗ = 𝑖⃗ − 2𝑗⃗ + 4𝑘⃗⃗
      𝑢
      𝑣⃗ = 2𝑖⃗ + 3𝑗⃗ − 𝑘⃗⃗
      ⃗⃗⃗ = 5𝑖⃗ + 4𝑗⃗ + 𝑘⃗⃗
      𝑤
                 1 −1 1                    −5 0 −2
                 2 −1 3                    −6 1  9
   6) Let, 𝐴 = [                                   ], 𝑟[𝐴] =?
                 1  0 2                    −1 0  3
                −1 2 0                     9 −1 −1
   7) For which values of the parameters ‘a’ and ‘b’ the system does have either i-unique solution
      or ii-no solution, where:
      x+y+z=3
      x+y+(1+2b+ab)z=3+2b
      (2+a)y+abz+b=b
   8) Find the angle between the given vectors:
      𝑎⃗ = (2,4,0), 𝑏⃗⃗ = (−1, −1,4)
   9) Let, 𝑎⃗x𝑏⃗⃗ = 4𝑖⃗ − 3𝑗⃗ + 6𝑘⃗⃗ and 𝑐⃗ = 2𝑖⃗ + 4𝑗⃗ − 𝑘⃗⃗ , Find the corresponding scalar or vector:
      (𝑎⃗x𝑏⃗⃗). 𝑐⃗=?
   10) Prove the following statements true or false:
       i)𝑎⃗x(𝑏⃗⃗x𝑐⃗) = (𝑎⃗x𝑏⃗⃗)x𝑐⃗ , ii)(𝑎⃗ + 𝑏⃗⃗)x(𝑎⃗ − 𝑏⃗⃗) = 2𝑏⃗⃗x𝑎⃗
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MIDDLE EAST TECHNICAL UNIVERSITY
    11) Use Gauss Elimination Method to solve the following system:
        2x1+2x2=0
        -2x1+x2+x3=0
        3x1+x3=0
    12) Use Gauss-Jordan Elimination Method to solve the following system:
        x1-2x2+x3=2
        3x1-x2+2x3=5
        2x1+x2+x3=1
    13) Check whether the following set of vectors are linearly dependent:
        i)     𝑢
               ⃗⃗1 = (1,2,3), 𝑢
                              ⃗⃗2 = (1,0,1) , 𝑢
                                              ⃗⃗3 = (1, −1,5)
        ii)    𝑢
               ⃗⃗1 = (2,6,3), 𝑢
                              ⃗⃗2 = (1, −1,4) , 𝑢⃗⃗3 = (3,2,1) , 𝑢
                                                                 ⃗⃗4 = (2,5,4)
                   2  3 4
    14) Let, 𝐴 = [ 1 −1 2] , Find: 𝑀12 , 𝑀32 , 𝐶13 , 𝐶22
                  −2 3 5
    15) Find the determinants of the following matrices by cofactor expansion for the given systems:
              0 2 0            5 0 0
        𝐴 = [3 0 1] , 𝐵 = [0 −3 0]
              0 5 8            0 0 2
    16) Find the determinant of the following system by using upper or lower triangular matrix form:
              1 1 5
        𝐴 = [ 4 3 6]
              0 −1 1
    17) Find the inverse of the following matrix:
              0 2 0
        𝐴 = [ 0 0 1]
              8 0 0
    18) Find the inverse of the following matrix by using Gauss-Jordan Method:
              1 2 3
        𝐴 = [ 4 5 6]
              7 8 9
    19) Find 𝑥⃗ for the following system if; 𝐴𝑥⃗ = 𝐵 and 𝐴−1 𝐴𝑥⃗ = 𝐴−1 𝐵 :
        x1+x2=4
        2x1-x2=14
    20) Solve the following system by using Cramer’s Rule:
        -3x1+x2=3
        2x1-4x2=-6
 Directions:
 -Solve each problem clearly with explicitly showing each step.
 -The due date will not be extended. The portal will not accept late submissions.
 -Problems are solely for you to solve.
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 and can easily be read and evaluated. Please check the neatness.
 -Name each document according to: <Name_LastName_ID>
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