Question

Choose the correct alternative:
If A = `[(1, 2, 2),(2, 1, -2),("a", 2, "b")]` is a matrix satisfying the equation AA^T = 9I, where I is 3 × 3 identity matrix, then the ordered pair (a, b) is equal to

Options

• (2, – 1)

• (– 2, 1)

• (2, 1)

• (– 2, – 1)

Answer 1

(– 2, – 1)