Question: differential with acceleration speed and actual distance.

Hello evrybody,

my first question here.

i'm a engineer studend in electronic and i'm working on the inverted pendulum problem at my university.

so i need to use the lagrange way to get my equations in the good form.

i have this equations :

( rd mean r with a dot upside. the diff by time, same for thetad, and thetadd, ... )

L = 1/2*(M1+M2)*rd^2+1/2*(j+m*l^2)*thetad^2+m*l*rd*thetad*cos(theta)-m*g*l*cos(theta)

my state vector is [ r ; theta ; rd ; thetad]

i can do the equations by hand but i would like to know how to check if i'm corect with the maple app.

to get the equations i need do lagrange :

d(diff(L,rd))/dt-diff(L,r)=F

d(diff(L,thetad))/dt-diff(L,theta)=0

My question is how to write well this equations in maple ?

i checked help but don't found how to set var_dot or something else that can be understandable by the app.

Thank you by advance.