JEE Main2026Apr 5, Shift 1Mathematics
Q.
Let be a matrix such that
, , and .
If , then is equal to :
- A
16
- B
25
- C
49
- D
64
Solution
The action of on standard basis vectors gives us its columns. From , the third column is . Subtracting from , the first column is .
From , the third row is . Subtracting from , the first row is .
Hence for some unknown . Expanding gives , which simplifies to , so .
Computing , so with .
For a matrix, , so .
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