I have searched my book front to back to find just one example of this type of problem and fond nothing. I

have also looked through both this forum and yahoo answers and saw nothing this ridiculous.

PLZ help me and save me from an anurism

Sin x = -2/5 x in quad 3

exact value of cos (x+Pi/4)

and the second seems easier but im afraid to try it

Exact value of sin 2x

I already did something i though helped, but got me no closer to the answer

sin x^2 + cos x^2 = 1

cos x^2 = 1+ 2/5^2=1 + 4/25=29/25=sqrt-29/25=sqrt-29/5

and this is where i contemplate my lifes worth..... This problem was on my final at OSU and i need a good grade! Help!