Given/Find Block with Matrix

[ptc-3449579]

I've seen this error several times on several different types of problems. I am defining a matrix as a find statement. However, the last variable in the matrix always comes back as "Variable is undefined.' I think this is a common error as I have seen it discussed before but I can never see the solution to prevent this from happening. I appreciate the help

[MikeArmstrong]

U1 is not defined anywhere.

Mike

[MikeArmstrong]

Actually, you haven't defined F either.

Mike

[wayne]

[Fred_Kohlhepp]

If you take the time to develop a symbolic solution (supplement file)

and solve for the values yu should get (second file) you get a "divide by zero" error. If you alter (very slightly) the value for k2 (the red highlight), the block will solve.

Congratulations, you have fallen victim (once again) to the lousy error reporting that we all know and love.