If A = 001010100, then A-1 is from Mathematics JE

Subject

Mathematics

Class

JEE Class 12

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 Multiple Choice QuestionsMultiple Choice Questions

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1.

If A = 001010100, then A-1 is

  • - A

  • A

  • 1

  • None of these


B.

A

We have, A = 001010100 A = 00 - 0 - 00 - 0 + 10 - 1 A = - 1and cofactors of A are       A11 = 0, A12 = 0, A13 = - 1       A21 = 0, A22 = - 1, A23 = 0       A31 = - 1, A32 = 0, A33 = 0 A-1 = adjAA = - 1100- 10- 10- 100 = A


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2.

If A = 685423971 is the sum of a symmetric matrix B and skew-symmetric matrix C, then B is :

  • 667625751

  • 02- 2- 25- 2220

  • 667- 62- 5- 751

  • 06- 220- 2- 2- 20


3.

If A = 1111, then A100 is equal to

  • 2100A

  • 299A

  • 100A

  • 299A


4.

If 1111- 2- 2131xyz = 034, then xyz is equal to :

  • 011

  • 12- 3

  • 5- 21

  • 1- 23


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5.

ddxtan-11 + x2 - 1x is equal to :

  • 11 + x2

  • x221 + x21 + x2 - 1

  • 21 + x2

  • 121 + x2


6.

ddxtan-11 + cosx21 - cosx2 is equal to :

  • - 1/4

  • 1/4

  • - 1/2

  • 1/2


7.

The maximum value of x1/x is :

  • 1/ee

  • e

  • e1/e

  • 1/e


8.

The function f defined by f(x) = 4x4 - 2x + 1 is increasing for :

  • x < 1

  • x > 0

  • x < 1/2

  • x > 1/2


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9.

A particle moves in a straight line so that s = t, then its acceleration is proportional to :

  • (velocity)3

  • velocity

  • (velocity)2

  • (velocity)3/2


10.

If A and B are 2 x 2 matrices, then which of the following is true ?

  • (A + B)2 = A2 + B2 + 2AB

  • (A - B)2 = A2 + B2 - 2AB

  • (A - B)(A + B) = A2 + AB - BA - B2

  • (A - B)(A + B) = A2 - B2


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