Question

How do you find the equivalent expression for `cot(x-pi/2)`?

Answer 1

`cot(x-pi/2)=-tanx`

Explanation:

We can use the identities `cot(-A)=-cotA` and `cot(pi/2-A)=tanA`

Hence `cot(x-pi/2)`

= `cot(-(pi/2-x))`

= `-cot(pi/2-x)`

= `-tanx`