Write the expression as the sine, cosine, or tangent of an angle. Then find the exact value of the expression. 4 2 tan tan 5 15 4 2 1+ tan tan 5 15 Write the expression as the sine, cosine, or tangent of a single angle. 4 2 tan tan 5 15 1 + tan tan 4 5 2 15 (Type an exact answer, using as needed. Use integers or fractions for any numbers in the expression.)