var('x,y,z,f1,f2,t')
f1 = y
u=diff(f1,y,1)
f2 = -x
v=diff(f2,x,1) 
integrate((v-u), (x,0,pi))

/*  Verification of Greens theorem */ 
f1 = y
f3=f1(sin(t))
f2= -x
f4=f2(cos(t),sin(t))
x=cos(t)
y=sin(t)
x1=diff(x)
y1=diff(y)
integrate((f3*x1)+(f4*y1),(t,0,2*pi))

Strang-9.4-3-U (last edited 2010-12-17 10:38:29 by xxx)