Question

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

Solution

1. Use the standard values: sin 60° = √3/2, cos 30° = √3/2, cos 60° = 1/2, and sin 30° = 1/2.
2. The expression = (√3/2)(√3/2) + (1/2)(1/2) = 3/4 + 1/4.
3. = 1.
4. This agrees with the formula sin(A + B) = sin A cos B + cos A sin B, since sin 90° = 1.