In my work they are asking for the exact values of

in all forms: Sin, Cos, Tan and recipricols by using double angle formula's. Sin and Cos of

make sense but i have a query involving Tan and Cotan.

i have figured out that

i have also figured out that

How would i go about figuring out

, Using the respective double angle formula didn't work so now i am stumped. Also i don't know at which point i should switch the numerator and denominator for Recipricol functions

and times by the conjugate to get the answer?

any help would greatly boost my confidence