Use Demoivre's Theorem to evaluate w^2, if w=3(cos30degs+ising30degs)
PS, it's really pi/6, but I converted it to 30 degrees since I can't write on the screen..
z^n=r^n(cos n*theta + i sin n*theta)
The Attempt at a Solution
w^2=3^2 (cos 2*30degs + i sin 2*30degs_
w^2=9(0.5+i [square root of 3]/2)
w^2=(9/2)+9i[square root of 3]/2
I copied the test review answer key.. but I'm not sure if I copied it down right..
The answer that I copied down was
9[square root of 3]/2 + i9[square root of 3]/2..
That answer would like like it would come from a 45deg thing.. but sinn and cosn are 60degs..
Just making sure.. So has anyone seen where I went wrong?