Question

cos(9pi/4+5pi/6)=

Answer 1

\[\cos(u+v)=\cos(u)\cos(v)-\sin(u)\sin(v)\] is what you need for this one

Answer 2

what does u and v stand for?

Answer 3

I wonder why they just didn't say \(\cos\left(\dfrac{37\pi}{12} \right)\)

Answer 4

set it up like this cos(9pi/4 + 5pi/6)=cos9pi/4(cos5pi/6)-sin9pi/4(sin5pi/6)=

Answer 5

@ParthKohli because you have no idea what that is

Answer 6

@satellite73 ?

Answer 7

OK well, Wolfram does.