Martha makes an error converting the complex number to polar form. Where did she make her error? Determine the correct answer and explain what Martha did wrong.
\(r=\sqrt{(-5\sqrt3)^2 +5^2}=\sqrt{25*3+25}=\sqrt{100}=10\)
\(\theta=arctan({5\over-5\sqrt3})={\pi\over6}\)
\(-5\sqrt3+5i=10(cos({\pi\over6})+i sin({\pi\over6})\)