How do you verify the identify costhetacscthetatantheta=1cosθcscθtanθ=1?

1 Answer
Aug 2, 2016

Please see below.

Explanation:

All trigonometric ratios can be easily expressed in terms of sinthetasinθ and costhetacosθ.

For example, tantheta=sintheta/costhetatanθ=sinθcosθ, cottheta=costheta/sinthetacotθ=cosθsinθ, sectheta=1/costhetasecθ=1cosθ and csctheta=1/sinthetacscθ=1sinθ

Hence, costhetacscthetatanthetacosθcscθtanθ

= costhetaxx1/sinthetaxxsintheta/costhetacosθ×1sinθ×sinθcosθ

= color(red)(cancel(costheta))xx1/cancel(sintheta)xxcancel(sintheta)/color(red)(cancel(costheta))

= 1