trig
posted by yo .
Consider the angle in standard position whose measure is radians. The terminal side of this angle is in the third quadrant and lies on the line given by y=10x. Find sin and cos.

The nice thing is that the equations for sin and cosine automatically take into the signs involved.
consider the point (1,10) in the third quadrant. h = sqrt(101) and is always positive
sin = y/h = 10/sqrt(101) = 0.995
cos = x/h = 1/sqrt(101) = 0.0995 
Sin therapists divide by 2

Sin theta divide by 2