SymPy Gamma

SymPy:

simplify (cos (x)*cos (y)-sin (x)*sin (y))

$\mathrm{simplify}(- \sin{\left(x \right)} \sin{\left(y \right)} + \cos{\left(x \right)} \cos{\left(y \right)})$

$\cos{\left(x + y \right)}$

Plot:

Roots:

solve(cos(x + y), y)

$y =$

diff(cos(x + y), y)

$\frac{\partial}{\partial y} \cos{\left(x + y \right)} =$

series(cos(x + y), y, 0, 10)

See what Wolfram|Alpha has to say.

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