Using SAGE math to differentiate or integrate a function

Differentiation
Need to differentiate a function? You can use the SAGE maths software. For example:
> diff(1/(1 - x^2), x)
2*x/(x^2 - 1)^2

Integration
We can integrate a function using "integral", for example:
> integral(2*x/(x^2 - 1)^2, x)
-1/(x^2 - 1)