How to create custom function in Mathcad

Greetings, I tried to create custom functions in mathcad but I was able to do it, however I wanted to create that function fc and fc1 and I couldn't, I get an error message I understand how to compile and tried other functions but when I go to do it with results of vectors and matrices I have this problem here I attach the code in C only for the fc function, could you help me how to create both custom functions please?