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# Second degree linear? diff equation with the first derivative squared

## Second degree linear? diff equation with the first derivative squared

(OP)
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)

### RE: Second degree linear? diff equation with the first derivative squared

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

### RE: Second degree linear? diff equation with the first derivative squared

(OP)
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...

### RE: Second degree linear? diff equation with the first derivative squared

View/Toolbars/Calculus.

### RE: Second degree linear? diff equation with the first derivative squared

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

### RE: Second degree linear? diff equation with the first derivative squared

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.

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