f1(x,y)=sin(x)*sqrt(y)+x;
q1,e1=integral2(f1,0,2,0,1);

f2(x,y,z)=ysin(x)+zcos(x);
q2,e2=integral3(f2,0,pi,0,1,-1,1);

f(y,x)=1;
a(x)=0
b(x)=sqrt(4-x^2);
q,e=integral2(f,0,2,a,b);
P=q/4;