> 123!;
> evalf(100!);
> 100!;
> evalf(Pi,20);
> simplify(a/b+c/d);
> expand((a+b+c)^2);
> factor(x^12-1);
> factor(x^12-1,3^(1/2));
> factor(x^12-1,I);
> factor(x^12-1,{3^(1/2),I});
> ifactor(2^100+1);
> diff(x^4,x$2);
> int(x^4,x);
> int(x^4*cos(3*x)*exp(2*x),x);
> evalf(int(cos(x^2),x=0..1));
> series(cos(x),x=0,20);
> combine(cos(a)*cos(b));
> expand(cos(a+b));
> combine(cos(a)*cos(b)*cos(c));
> solve(x^2-3*x-7);
> solve({2*x+3=4,3*x-y=1});
> solve({x+y+z=1,2*x+y-3=0},{x,y});
> simplify(1/(1+1/(1+x)));
> sum(k^2,k=1..20);
> sum(k^2,k=1..n);
> implicitdiff(x^2*y+y^3*x-y,y,x);
> series(x/cos(x^2+x),x=0,10);
> evalf(exp(Pi*163^(1/2)),30);
>