how do i solve for sinxcosx + 2cosx = 0

Question

psymon · Answer

There is a way you can factor this some. Factor it slightly and then set each factor equal to 0 and solve. Can you see what you factor out?

anonymous · Answer

cosx

psymon · Answer

Right. So that gives you

cosx(sinx + 2) = 0    so you would set each factor equal to 0

cosx = 0
sinx + 2 = 0

Of course that bottom factor has an issue with it if you maybe recognize it.

anonymous · Answer

yes the plus 2, so how do i solve for that?

psymon · Answer

You cant. 
sinx =-2

But the range of the sin function isonly [-1,1], meaning there is no answer for that factor. That means you're only answers will come from cosx = 0

anonymous · Answer

so the answer is just pi/2 and 3pi/2?

psymon · Answer

Yep : )

anonymous · Answer

woohoo thanks! i appreciate it

psymon · Answer

Yeah, np :3