Question

If tan a=√2-1 show that tan a/1-tan^2a=√2/4

Answer 1

Given ΔACB right angled at C in which AB = 29 units , BC = 21 units and ∠ABC = θ . Determine the values of:(i) cos2θ +sin2θ   (ii) cos2θ - sin2θ2 – 1, AB = 1 In right angled ΔABC, AC2 = AB2 + BC 2 [By Pythagoras theorem] ⇒ AC2 = 12 + (√2 – 1)2 ⇒ AC2 = 1 + + 2 – 2√2 + 1 = 4– 2√2