Write the expression as either the sine, cosine, or tangent of a single angle.

cos(pi/3)cos(pi/5)+sin(pi/3)sin(pi/ 5)

Adam plans to choose a video game from the section of the store where everything is 75% off. he writes the expression d-0.75d to find the sale price of the game if the original price is d dollars. gena correctly writes another expression, 0.25d, that will also find the sale price of the game if the original price is d dollars. use the drop down menus to explain each part of adams and rena's expression

Abacteria population is tripling every hour. by what factor does the population change in 1/2 hour? select all that apply

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.