Write cos(theta) in terms of sin(theta) only

Question

I need to express cos(theta) in terms of sin(theta) only. Thank you in advance for your help. 

Answer 1

cos²θ + sin²θ = 1, so cos²θ = 1 - sin²θ

 

                              Therefore, cosθ = ±√(1-sin²θ)

Answer 2

Sin^2 THETA  + Cos^2 THETA  = 1

 

use this identity and move forward

 

Cos THETA = sqroot (1 - sin^2 THETA )

 

thus we have cosine just in terms of sine. Hope it helps thanks.