Write the expression as the sine, cosine, or tangent of an angle. Then find the exact value of the expression. tan 15° + tan 30° 1-tan 15° tan 30° ... Rewrite the expression using a sum or difference formula. Choose the correct answer below. O A. sin(15° -30°) OB. tan (15° -30°) O c. tan (15° +30°) D. cos(15° +30°) Write the expression as the sine, cosine, or tangent of a single angle. tan 15° + tan 30° 1- tan 15° tan 30° Find the exact value of the expression. tan 15° + tan 30° 1-tan 15° tan 30° (Type an exact answer in fraction format, using radicals as needed, and rationalize any denominator.)