Question

(1+tanA)² + (1-tanA)² = 2sec²A​

Answer 1

Answer:

LHS = (1+tanA)² + (1-tanA)²

1² + 2tanA + tan²A + 1² - 2tanA + tan²A

1 + 1 + tan²A + tan²A + 2tanA - 2tanA

2 + 2tan²A

2(1 + tan²A)

2sec²A = RHS (since 1+tan²A=sec²A)

Hence proved