restart;
int((x^3+x^2)*(x+3),x=0..1);

int(x*exp(2*x),x=0..1);

I1:=int(1/(3+x^2),x=-1..1);

I1;

simplify(I1);

Digits:=50;

evalf(I1);

Digits:=10;

plot(x*sin(x),x=-4*Pi..4*Pi);

y:=x*sin(x);

dy:=diff(y,x);

solve(dy=0);

fsolve(dy=0,x=10);