91Ó°ÊÓ

For the following exercises, evaluate the product for the given expression using a sum or difference of two functions. Write the exact answer. $$ \cos \left(\frac{\pi}{3}\right) \sin \left(\frac{\pi}{4}\right) $$

For the following exercises, evaluate the product for the given expression using a sum or difference of two functions. Write the exact answer. $$ 2 \sin \left(\frac{2 \pi}{3}\right) \sin \left(\frac{5 \pi}{6}\right) $$

For the following exercises, evaluate the product for the given expression using a sum or difference of two functions. Write the exact answer. $$ 2 \cos \left(\frac{\pi}{5}\right) \cos \left(\frac{\pi}{3}\right) $$

For the following exercises, evaluate the sum by using a product formula. Write the exact answer. $$ \cos \left(\frac{5 \pi}{12}\right)+\cos \left(\frac{7 \pi}{12}\right) $$

For the following exercises, change the functions from a product to a sum or a sum to a product. $$ \sin (9 x) \cos (3 x) $$

For the following exercises, change the functions from a product to a sum or a sum to a product. $$ \cos (7 x) \cos (12 x) $$

For the following exercises, change the functions from a product to a sum or a sum to a product. $$ \sin (11 x)+\sin (2 x) $$

For the following exercises, change the functions from a product to a sum or a sum to a product. $$ \cos (6 x)+\cos (5 x) $$

For the following exercises, find all exact solutions on the interval \([0,2 \pi)\) $$ \tan x+1=0 $$

For the following exercises, find all exact solutions on the interval \([0,2 \pi)\) $$ 2 \sin (2 x)+\sqrt{2}=0 $$