Trigonometry

Using the trigonometric identity , and substituting , we find that .

Using the formula for the difference of cosines and sines, we can simplify this expression and find that the result is .

Using the identity , we simplify the expression: Substituting these values into the expression: Factor out : Since , the entire expression simplifies to: Thus, the correct answer is 0.

We begin by simplifying the given trigonometric expression. Using the following trigonometric identities: Substitute these identities into the expression: Simplifying: Therefore, the correct answer is 0.

We use the identity to simplify the expression: Thus, the correct answer is .

We are given that , which implies that . Using the identity: Substituting the value of , we get: Thus, . Now, using the identity: Therefore, the correct answer is .