Question

If 5A= ☝️and AA^T = A^T A= I then x =
​

Answer 1

• this is the definition of the orthogonal matrix.

We know for an orthogonal matrix ∣A∣=±1.

Then we have,

(3x+16)=±1 [ Since the order of the matrix is 2]

or, 3x+16=±25

or, 3x=25−16 [ Taking the positive value]

or, 3x=9

or, x=3.