Correct Answer: A x H = G2
Explanation:
A = (a + b)/2, 1/H = (1/a + 1/b)/2 ⇒ H = 2ab/(a +b), G = √ab ∴ A x H = {(a + b)/2} x {2ab/(a + b)} = ab = G2 ∴ A x H = G2