JAMIA 2023 β Mathematics PYQ
JAMIA | Mathematics | 2023If π΄2−π΄=3πΌ then π΄−1 is
Choose the correct answer:
- A.
A-I
- B.
1/3 (π΄−πΌ)
(Correct Answer) - C.
A+ I
- D.
1/3 (π΄+πΌ)
1/3 (π΄−πΌ)
Explanation
1. Given Equation
The equation provided is:
A2βA=3I
2. Isolate the Identity Matrix
Since we want to find Aβ1, we need to manipulate the equation so that I is on one side. The equation is already in that form:
A2βA=3I
3. Factor out Matrix A
On the left side of the equation, we can factor out A from both terms. Note that when we factor A out of A, it leaves the Identity matrix I:
A(AβI)=3I
4. Solve for Aβ1
To get Aβ1, we multiply both sides of the equation by Aβ1 from the left:
Aβ1β
[A(AβI)]=Aβ1β
(3I)
Using the property Aβ1A=I:
I(AβI)=3Aβ1
AβI=3Aβ1
5. Final Result
Now, divide both sides by 3 to isolate Aβ1:
Aβ1=31β(AβI)

