We are given the following trigonometric expression:
We are asked to put this expression as a function of sines and cosines, t do this, let's remember the following relationship:
Now we replace this in the expression:
Now we do the operation in the numerator, like this:
We simplify the result:
now we use the following relationship:
replacing this in the expression
simplifying:
Since we are asked to put the expression as a function of sines and cosines we can't simplify any further, therefore the previous expression is the result.