Evaluate sin(60°)cos(30°) + cos(60°)sin(30°).

Explanation

• The expression matches the identity sin A cos B + cos A sin B = sin(A + B).
• So it equals sin(60° + 30°) = sin 90° = 1.
• The long route agrees: (√3/2)(√3/2) + (1/2)(1/2) = 3/4 + 1/4 = 1.
• Option D √3 appears if the second term is dropped, so both products must be added.
• The companion identity is cos A cos B − sin A sin B = cos(A + B), which is worth learning next to this one.