Question

Given sinθ = 5/9, where π/2 < θ < π, find the exact values of sin 2θ and cos 2θ.

Answer 1

Im working it out again, but is the correct answer 10/9, -(4√14)/9

Answer 2

start by drawing a triangle in the 2nd quadrant



fin x, its negative...

then you can find cos(@)

and finally substitute the values into

\[\sin(2\theta) = 2 \sin(\theta)\cos(\theta)\]

and

\[\cos(2\theta) = \cos^2(\theta) - \sin^2(\theta)\]

hope it helps