I am fairly novice user of MathCAD. I am using version 14. I am trying to multiply a diagonalized 3x3 matrix containing only variables with another matrix completely populated with numbers and no variables. However, when I create the 3x3 matrix with only variables, the variables are highlighted and MathCAD tells me “the variable is undefined”. I am hoping to multiply these to matrices and have a result with the variables multiplied by constants. I know this can easily be done by hand, but I would like to learn how to do this with MathCAD so I can be prepared when I have to multiply larger matrices in the future. Any thoughts?