Answer:
See the proof below
Step-by-step explanation:
For this case we need to proof the following identity:
We need to begin with the definition of tangent:
So we can replace into our formula and we got:
(1)
We have the following identities useful for this case:
If we apply the identities into our equation (1) we got:
(2)
Now we can divide the numerator and denominato from expression (2) by and we got this:
And simplifying we got:
And this identity is satisfied for all:
