Which is a stag?

Solve the equation for exact solutions

Use identities to find value of 

Use a sum or difference formula to find the exact value of the trigonometric function

Simplify the algebraic expression and the corresponding trigonometric expression.

Write the given expression as a function of x.

Find the solutions to the equation in the interval 

Find all solutions of this equation:

Complete the identity

Use an identity to evaluate the expression