Answer:
Step-by-step explanation:
The given expression is
To find the exact value using identities, we can split the angle in a sum that is equivalent, that is, we rewrite the expression.
Let's rewrite the expression
We can rewrite this way, because the sum of those fractions gives the original one. Then, we simplify
Now, here we need to transfor from radians to degrees, because that way we can obtain half-angles
Then, we divide each fraction in a way that the final expression contains halves
The half-angle identity is
In this case, , replaing it in the identity, we have
But, , replacing this