Input: sum(k^2,k,0,x)
Write: `sum(k^2,k,0,x)`
Output: $$ \sum _{k=0} ^ {x} {k}^{2} == \frac{1}{6}\ x+\frac{1}{2}\ {x}^{2}+\frac{1}{3}\ {x}^{3} $$ Result:$$\frac{1}{6}\ x+\frac{1}{2}\ {x}^{2}+\frac{1}{3}\ {x}^{3}$$