Question

Determine Whether the following equations are identities: (a)cos²θ+sec²θ=2tanθ/1+tan²θ (b)sin2θ=2tanθ/1-tan²θ

Answer 1

Answer:

Step-by-step explanation:

Sin²θ + Cos²θ = 1. Tan²θ + 1 = Sec²θ ... Edited : Cos(A - B) - Cos(A + B) = 2SinASinB. SinC + SinD ... Sin2θ = 2SinθCosθ = (2tanθ)/(1+tan²θ). Cos2θ = Cos²θ - Sin²θ = 2Cos²θ - 1= 1 - 2Sin²θ = (1-tan²θ)/(1+tan²θ)