Question: Which of the following is the correct formula for the sine of a sum?

Options:

1. sin(a + b) = sin(a) + sin(b)
2. sin(a + b) = sin(a)cos(b) + cos(a)sin(b)
3. sin(a + b) = sin(a)sin(b)
4. sin(a + b) = cos(a) + cos(b)

Correct Answer: sin(a + b) = sin(a)cos(b) + cos(a)sin(b)

Solution:

The sine of a sum is given by sin(a + b) = sin(a)cos(b) + cos(a)sin(b).