Question

How do you prove that `sinthetacostheta=cottheta` is not an identity by showing a counterexample?

Answer 1

we just need one value to show this.

Explanation:

`"take "theta=45^0 " and work out teh approriate values"`

`LHS, " "sin45xxcos45=sqrt2/2xxsqrt2/2=2/4=1/2`

`RHS cot45=1/tan45=1/1=1`

`:.sin45cos45!=cot45`