Write the expression as the sine, cosine, or tangent of an angle. Then find the exact value of the expression. sin 40° cos 20° + cos 40° sin 20° Rewrite the expression using a sum or difference formula. Choose the correct answer below. O A. cos (40° - 20°) O B. cos (40° + 20°) Oc. sin (40° - 20°) D. sin (40° + 20°) Write the expression as the sine, cosine, or tangent of an angle. sin 40° cos 20° + cos 40° sin 20° = (Type an exact answer, using x as needed. Use integers or fractions for any numbers in the expression.) Find the exact value of the expression. sin 40° cos 20° + cos 40° sin 20° = (Simplify your answer. Type an exact answer, using radicals as needed. Use integers or fractions for any numbers in the expression. I