# Question:Inverse of trigonometric symbolic 6x6 matrix

## Question:Inverse of trigonometric symbolic 6x6 matrix

Maple

Hello,

i am currently trying to get some equation of motions. For this i have to invert a matrix which looks like this:

A = GL * M * GL.'     (6x6)

M is the massmatrix. GL is a matrix with kinematic constraints because i am working on a closed loop subject. The problem is that GL consists of symbolic trigonometric terms which i can't replace with numbers. Because of the multiplication with the transpose and the massmatrix the elements of A get really really long. In my opinion too long to get the inverse.

Until now i have only tried to calculate the inv(A) with matlab but here i always get an "internal error c0000005".I have read some topics that there could be a problem with the pivotelement in case of symbolic calculation.

Now I want to try to get the inverse in maple because this program seems to be better for a symbolic calculation. I don't know if i will have problems with the pivotelements because all elements of A are nonzero. Do i have to switch of the use of pivot? How do i do that?

Will it be better to calculate the inverse by inv(A) = 1/det(A) * adj(A) ? I haven't found a command to calculate the adjoint.

It would be nice if someone knows how to solve my problem. Otherwise i could not reach the aim of my master's thesis. Thank you.

Phil

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