Question

Use the product-to-sum formula to convert the expression to a sum or difference. Simplify where is possible. ​

Answer 1

Answer:

sin3t*cos(s)*cos(t)+sin3t*sin(s)*sin(t).

Step-by-step explanation:

sin3t*cos(s-t);

1) cos(s-t)=cos(s)cost+sin(s)sint; then

2) sin3t*cos(s-t)=sin3t*cos(s)*cos(t)+sin3t*sin(s)*sin(t).