Question

sex(-x)-sin(-x)tan(-x)=cosx Note that each Statement must be based on a Rule chosen from the Rule menu. To see a detailed description of a Rule, select the More Information Button to the right of the Rule.

Answer 1

Explanation:

sec (-x)-sin (-x) tan (-x)=cos x

sec(x)-(-sin x)(-tan x)=cos x

1/cos x-sin x(sin x/cos x)=cos x

multiply by cos x

1-sin ²x=cos²x

or 1=sin²x+cos²x

which is true.