# cosine and sine..

• November 3rd 2008, 11:43 PM
zuuberbat
cosine and sine..
Find all angles t, where 0 < or = t < 2pi, that satisfy the given condition.

a) cost = -1
b) sint = 1/2

Find all angles theta (symbol), where 0° < or = theta < 360°, that satisfy the given condition.

a) sin theta = -1/2
b) cos theta = 1

I kinda forgot how to find these, any help appreciated. Don't really remember the special triangles if that's what's needed to solve these.. ><.

Explanations and steps would really help, thanks a lot.
• November 4th 2008, 12:49 AM
toraj58
$\sin (\theta) = \sin (2n\pi + \theta)$
$\sin (\theta) = \sin ((2n+1)\pi - \theta)$