Second degree linear? diff equation with the first derivative squared

[blckwtr]

I get an error message telling me I have too many equations in the solve block. I tried to use the Odesolve function. Is there another solution for my problem?

example:

Given

m*x''(t)+c*(x'(t))^2+k*x(t)=0

x(0)=0 x(0)=5

x:=Odesolve(t,2)

 

[wfn217]

I have Mathcad 2001 and it works. Be sure you are typing x'(0)=5 and not dx(0)/dt=5.

 

[blckwtr]

Thanks, if this works I would be very happy. How do you type the nth derivative operators, by the way? I think I have tried all the combinations...

 

[wfn217]

View/Toolbars/Calculus.

 

[blckwtr]

But the dot, not the d/d. You said I must type '', not d/d...

 

[wfn217]

Just hit the "prime" key on the keyboard twice. This key is probably on the upper left corner of your keyboard. It is OK to use d/d in the differential equation, but use the "prime" for the initial condition of the first derivative.