Home
Class 12
MATHS
If A = {:((1,-1),(1,2)):}and {:((1,0),(0...

If `A = {:((1,-1),(1,2)):}`and `{:((1,0),(0,1)):}` then `3A^(-1)` is equal to :

A

`3I - A`

B

`4I - A`

C

`6I - A`

D

`A- 6I`

Text Solution

Verified by Experts

The correct Answer is:
A
`A = ({:(1,-1),(1,2):}) , |A|=3`
`A^(-1) = (adjA)/(|A|) =(({:(2,1),(-1,1):}))/(3) , " " 3A^(-1) =({:(2,1),(-1,1):})= 3I - A`
Promotional Banner

Topper's Solved these Questions

  • MOCK TEST 7

    VMC MODULES ENGLISH|Exercise MATHEMATICS (SECTION 2)|5 Videos

  • MOCK TEST 6

    VMC MODULES ENGLISH|Exercise MATHEMATICS (SECTION 2)|5 Videos

  • MOCK TEST 8

    VMC MODULES ENGLISH|Exercise MATHMATICS (SECTION 2)|5 Videos

Similar Questions

Explore conceptually related problems

If A = {:((1,-1),(1,2)):} and I={:((1,0),(0,1)):} then 3A^(-1) is equal to :

If A=[{:(0,1),(1,0):}] then A^(2) is equal to

If A = [(1,0),(1/2,1)] , then A^100 is equal to

If A=[{:(1,0,0),(0,1,0),(a,b,-1):}] then A^(2) is equal to

If A=[{:(1,0,0),(0,1,0),(a,b,-1):}] then A^(2) is equal to

If A=[{:(,3,1),(,-1,2):}] and I=[{:(,1,0),(,0,1):}] ,find A^2-5A+7I .

(i) if A=[{:(1,0),(0,1):}],B=[{:(0,1),(1,0):}]and C=[{:(1,0),(0,1):}], then show that A^(2)=B^(2)=C^(2)=I_(2). (ii) if A=[{:(1,0),(1,1):}],B=[{:(2,0),(1,1):}]and C=[{:(-1,2),(3,1):}], then show that A(B+C)=AB+AC. (iii) if A=[{:(1,-1),(-1,1):}]and B=[{:(1,1),(1,1):}], then show that AB is a zero matrix.

If X+{:[(2,1),(6,1)]:}={:[(1,1),(0,1)]:} then 'X' is equal to

If the matrix A is such that ({:(1,3),(0,1):})A=({:(1,1),(0,-1):}) , then what is A equal to ?

Let A=((1,0,0),(2,1,0),(3,2,1)) . If u_(1) and u_(2) are column matrices such that Au_(1)=((1),(0),(0)) and Au_(2)=((0),(1),(0)) , then u_(1)+u_(2) is equal to :