Simplify
Use www.mathway.com/precalc
Its a good site calculator.
It just says undefined on that website
\(\frac{cos(-\theta)cot(-\theta)}{cosec(\theta)}\\ =cos(\theta)*\frac{cos(-\theta)}{sin(-\theta)}\div\frac{1}{sin(\theta)}\\ =cos(\theta)*\frac{cos(\theta)}{-sin(\theta)}*\frac{sin(\theta)}{1}\\ =-cos^2(\theta)\)
