hi again.. and thank you again for the answers.. I got it to work with something like Mariner's suggestion: v := subs(løsning, diff(y(x), x)) can anyone tell me why it doesn't work when I type diff(y(x),x) instead of y'(x)? /peter

hi again.. and thank you again for the answers.. I got it to work with something like Mariner's suggestion: v := subs(løsning, diff(y(x), x)) can anyone tell me why it doesn't work when I type diff(y(x),x) instead of y'(x)? /peter

hi.. thank you for you help - but I'm sorry to tell you that it did not work.. /peter

hi.. thank you for you help - but I'm sorry to tell you that it did not work.. /peter