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/4))
)

Kreyszig-9.4-3-U (last edited 2010-12-18 07:52:27 by xxx)