Chapter 1, Problem 14P

Define two variables: $alpha=\pi /6$ , and $beta=3\pi /8$ . Using these variables, show that the following trigonometric identity is corrected by calculating the values of the left and right sides of the equation.

$\sin \alpha +\sin \beta =2\left(\frac{\alpha +\beta }{2}\right)\cos \left(\frac{\alpha -\beta }{2}\right)$