Ahh... with IE I can see the taskbar (before I used chrome)! The code is (hopefully) attached and the important parts are commented.View 11284_demo.mw on MapleNet or Download 11284_demo.mw
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Thank you for your code example! It helped a lot! Nevertheless I don't understand why int(..) has worked perfectly all the other times I integrated a piecewise function. Sometimes the behavior of Maple is strange!!! Nevertheless thanks a lot! Grüße, Flo

Ok! Of the function Vd := proc (eta, xi) options operator, arrow; ((-1)*0.2893279480e-4*xi^6+0.2068912225e-5*xi^8+0.9156907035e-3*xi^2+0.2109192340e-3*xi^4)*cos(eta)+((-1)*0.6071284941e-4*xi^7+0.9066131648e-3*xi^5+(-1)*0.6001066340e-2*xi^3+(-1)*0.4141132509e-1*xi)*sin(eta)+.5000000000*kp*eta^2 end proc; I want to get the surface area with the value Vd(eta,xi)=0.0162. Thanks for your help. Flo