Question

How do you verify the identity `csc^4x-2csc^2x+1=cot^4x`?

Answer 1

see below

Explanation:

Right Hand Side :

Use the identity:
`1+cot^2x=csc^2x`

`cot^4x=cot^2x * cot^2 x`

`=(csc^2x-1)(csc^2x-1)` -----> FOIL

`=csc^4x-2csc^2x+1`

`:.=` Left Hand Side