Taylor approximation of a differential equation

Hello everyone,

I'm new to Maxima and struggling with the following problem:
Let's assume there is an Expression that depends on a variable and its  
derivative,
like for example:


	depends(q, t);
	x: sin(q) + diff(q, t)^2;


I would like to linearise x with respect to q and d/dt q.
The first thing I tried was to calculate the first-order Taylor  
approximation like this:


	taylor(x, [q, diff(q, t)], [1, 2], 1);


But this only leads to the error: "taylor: d/dt q cannot be a variable".
Is there a way to achieve this in Maxima without substituting the  
derivatives for new variables?

Any help would be appreciated.


Regards,
Stefan