Answer:
Explanation:
Use the formulas supplied in the picture attached. There's nothing to really learn here, it is just a plug-and-chug formula:
![sin(3x)sin(2x)=(1)/(2) [cos(3x-2x)-cos(3x+2x)]](https://img.qammunity.org/2023/formulas/mathematics/high-school/t3eb5tgxkyppzheldrhvnb96akj43iv2kk.png)
![sin(3x)sin(2x)=(1)/(2) [cos(x)-cos(5x)]](https://img.qammunity.org/2023/formulas/mathematics/high-school/s1ecztq3v2rdyale6va1hqlmbl17wgxvnq.png)
Moving on to the second problem:
![cos(a)sin(b)=(1)/(2)[ sin(a+b)-sin(a-b)]](https://img.qammunity.org/2023/formulas/mathematics/high-school/wroswvs22sy0av16ja75tp734hpald40y2.png)
Therefore:

Where:


Solve for 'a' using the second equation to get:

Plug this into the first equation to get:




Therefore:


Finally:
