JEE 2023 — Mathematics PYQ
JEE | Mathematics | 2023If A and B are two non-zero n×n matrices such that A2+B=A2B, then
Choose the correct answer:
- A.
A2=I or B=I
- B.
A2B=I
- C.
AB=I
A2B=BA2
Explanation
Solution
Di gayi equation ko rearrange karte hain:
A2+B=A2B
A2B−A2−B=0
Dono sides mein Identity matrix I jodte hain taaki factorization ho sake:
A2B−A2−B+I=I
(A2−I)(B−I)=I
Chunki (A2−I) aur (B−I) ek dusre ke inverse hain, ye commute karenge:
(A2−I)(B−I)=(B−I)(A2−I)
Ise expand karne par:
A2B−A2−B+I=BA2−B−A2+I
A2B=BA2
Explanation
Solution
Di gayi equation ko rearrange karte hain:
A2+B=A2B
A2B−A2−B=0
Dono sides mein Identity matrix I jodte hain taaki factorization ho sake:
A2B−A2−B+I=I
(A2−I)(B−I)=I
Chunki (A2−I) aur (B−I) ek dusre ke inverse hain, ye commute karenge:
(A2−I)(B−I)=(B−I)(A2−I)
Ise expand karne par:
A2B−A2−B+I=BA2−B−A2+I
A2B=BA2

