KENDRIYA VIDYALAYA RWF YELAHANKA, BENGALURU – 560064
HOLIDAY ASSIGNMENT
1. Construct a 3 x3 matrix A = ( a ij ) when a ij = 5i + 3 j ,if i¿ j
                                                           =7             , if i =j
                                                               = 4i – 3 j ,if i¿ j
                                   ( ) ( )( )
                                     2
                                   x       x   −2
2. Solve for x and y when            2 −3    =
                                   y      2y   −9
             (5 1 )
3. If A = 2 3 , Verify that A2 −8 A + 13 I = O and hence find A3
             ( 0 1)
4. If A = −1 0                     (3 7 )
                         and B = 5 2 , , verify that P = B AB’ is a skew symmetric matrix
5. Using determinants , find the value of x for which the three points
      A ( x , 2 −¿2x ) B ( −x +1 ,2 x ¿∧C (−4−x , 6−2 x ) are collinear
             (                 )
                2    3 −1
6.    If A =  x+  4 −1  2 is singular matrix , find the value of x
             3 x +1 2 −1
7. Let A = 3     (2   −1
                       4), B = ( )
                               5 2
                               7 4 , and C =
                                             2 5
                                                 ( )
                                             3 8 , find the matrix D such that
           CD – AB =O
           ( )
          1 1 1
8. If A = 1 0 2 , find A−1 . Using A−1 ,solve                  x+y+z=6               ,x+2z=7
          3 1 1
     3x + y + z = 12
            [            ]           [           ]
            1 −2 0          7 2 −6
9. . If A = 2  1 3 and B = −2 1 −3 , find AB. Hence, solve the system of equations:
            0 −2 1         −4 2 5
x – 2y = 10;          2x + y + 3z = 8       and –2y + z = 7.
10 . A school wants to award its students for the values of Honesty, Regularity and Hard
work with a total cash award of Rs.6, 000/–. Three times the award money for Hard work
added to that given for Honesty amounts to Rs.11, 000/–. The award money given for
Honesty and Hard work together is double the one given for Regularity. Represent the above
situation algebraically and find the award money for each value, using matrix method