Numerical integration
Define a function f(x) to integrate on [0,1] .
> f := x->(16-16*x^2)^(1/2);
> readlib(`evalf/int`):
> Digits := 13;
> F1 := `evalf/int`(f,0..1,Digits);
Try again at higher precision
> Digits := 36;
> F2 := `evalf/int`(f,0..1,Digits);
Compare with the exact answer .
> pi := evalf(Pi);
> zero_3 := pi-F2;