Hi,

I need to simplify this equation:

$\displaystyle \sqrt{(-2\sin{2t})^2 + (2\cos{2t})^2}$

I know that this equals 2 (by plugging into a calculator). However, I can't figure out the steps to simplify it. This is what I have... could someone show me what I'm doing wrong?

$\displaystyle \sqrt{-4\sin^2{2t} + 4\cos^2{2t}}$

$\displaystyle \sqrt{4(\cos^2{2t} - \sin^2{2t})}$

$\displaystyle 2 \sqrt{1 - 2\sin^2{2t}}$

but I'm not sure where to go from here...