__ _cos b =1/2[sin(a+b)+sin(a-b)] a) cos b b) sin b c) sin a d) cos a

sin a

Step-by-step explanation:

let the unknown term be x.

you have to remember that:

2sinAcosB=sin(A+B)+sin(A-B)

step-by-step explanation:

once you graph it hit 2nd (the blue button) and graph

that takes you to a table of coordinates

on the left is x coordinates and on the right is y coordinates and an empty box

(you may have to scroll up/down in order to get ( x, 0)