For a matrix A = 100210321, if U1, U2, and U3. are

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 Multiple Choice QuestionsMultiple Choice Questions

231.

If f(x) = 1xx + 12xx(x - 1)x + 1x3xx - 1x(x - 1)x - 2x + 1xx - 1

Then, f(100) is equal to

  • 0

  • 1

  • 100

  • 10


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232.

For a matrix A = 100210321, if U1, U2, and U3. are 3 × 1 column matrices satisfying AU1 = 100, AU2 = 230, AU3 = 231 and U is 3 × 3  matrix whose columns are U1, U2, and U3.  Then, sum of the elements of U- 1

  • 6

  • 0

  • 1

  • 2/3


B.

0

Let 

Ui = aibici, where i = 1, 2, 3 AU1 = 100210321a1b1c1 a12a1 + b13a1 + 2b1 + c1 = 100           AU1 = 100

 a1 = 1, 2a1 + b1 = 0 2 + b1 = 0 b1 = - 2and 3a1 + 2b1 + c1 = 0 3 + 2- 2 + c1 = 0 3 - 4 + c1 = 0 c1 = 1

Similarly, AU2100210321a2b2c2

a22a2 + b23a2 + 2b2 + c2 = 230        AU2 = 230

 a2 = 2 and 2a2 + b2 = 3 2 × 2 + b2 = 3 4 + b2 = 3 b2 = - 1and 3a2 + 2b2 + c2 = 0 3 × 2 +2- 1 + c2 = 0 6 - 2 + c2 = 0 c2 = - 4

Now, AU3100210321a3b3c3

a32a3 + b33a3 + 2b3 + c3 = 230        AU3 = 230

 a3 = 2 and 2a3 + b3 = 3 2 × 2 + b3 = 3 4 + b3 = 3 b3 = - 1and 3a3 + 2b3 + c3 = 1 3 × 2 +2- 1 + c3 = 1 6 - 2 + c3 = 1 c2 = - 3

 U = 122- 2- 1- 11- 4- 3 U = 13 - 4 - 26 + 1 + 28 + 1           = - 1 - 14 + 18 = 3Also, adjU = - 1- 79- 2- 560- 33T = - 1- 20- 7- 5- 3963 U- 1 = 1UadjU

 U- 1 = - 13- 230- 73- 53- 1321

Hence, the sum of all elements of u- 1 is 0


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233.

Let I denote the 3 x 3 identity matrix and P be a matrix obtained by rearranging the columns of I. Then,

  • there are six distinct choices for P and det (P) = 1

  • there are six distinct choices for P and det (P) =  ± 1

  • there are more than one choices for P and some of them are not invertible

  • there are more than one choices for P and P- 1 = I in each choice


234.

If I = 100010001 and P = 1000- 1000- 2. Then, the matrix P3 + 2P2 is equal to

  • P

  • I - P

  • 2I + P

  • 2I - P


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235.

If P = 2- 2- 4- 1341- 2- 3, then P5 is equal to

  • P

  • 2P

  • - P

  • - 2P


236.

The system of linear equations λx + y + z = 3,  x - y - 2z = 6, - x + y + z = µ has

  • infinite number of solutions for λ -1 and all µ

  • infinite number of solutions for λ = - 1 and μ = 3

  • no solution for λ  - 1

  • unique solution for λ = - 1 and μ = 3


237.

If A and B are two matrices such that A + B and AB are both defined, then

  • A and B can be any matrices

  • A, B are square matrices not necessarily of the same order

  • A, B are square matrices of the same order

  • number of columns of A = number of rows of B


238.

If A = 3x - 12x +3x + 2 is a symmetric matrix, then the value of x is

  • 4

  • 3

  • - 4

  • - 3


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 Multiple Choice QuestionsShort Answer Type

239.

If A, B are two square matrices such that AB = A and BA = B, then prove that B2 = B


 Multiple Choice QuestionsMultiple Choice Questions

240.

If the matrices A = 213410 and B = 1- 10250, then AB will be

  • 1704- 2

  • 4004

  • 1740- 2

  • 0000


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