diff ((sin (x)*x**2)/(1+tan (cot (x))))

diff(x**2*sin(x)/(tan(cot(x)) + 1), x)

solve(x**2*sin(x)/(tan(cot(x)) + 1), x)

series(x**2*sin(x)/(tan(cot(x)) + 1), x, 0, 10)

Want to compute something more complicated? Try a full Python/SymPy console at SymPy Live.