Loading [MathJax]/jax/output/HTML-CSS/jax.js

Prove that Cos(90θ) = Sinθ.

Solution :

Draw a right angled triangle ABC right angled at B.theta

Let A = θ,  then C = 90 – θ

sin A = sinθ = BCAC                     ……..(1)

cos C = cos(90θ) = BCAC             ……..(2)

From (1) and (2), we have

cos(90θ) = sinθ

Leave a Comment

Your email address will not be published. Required fields are marked *