Using the range ß you created the vector FSL2, whose values correspond with the index, which is supposed to be an angle in degree.
You already got the maximum value of FSL2 and obviously you are searching for the appropriate index/angle. You could get it using match(FmaxSL2, FSL2)=... or Match(FmaxSL2, FSL2,"near")=...
But the approach you have chosen is very limited and undesirable.
The function f you created simply looks up the appropriate value in the vector and returns it. That kind of discrete function is not suitable for a numerical algorithm used in maximize, which changes the argument in small increments to see which direction to go further.
You should get rid of your range ß and turn all your a,b,c, HLR, etc. into true functions of ß. Like a(ß):=cos(ß)*COG, etc. Don't use deg in the function definition - let Mathcad handle the units.
If you have troubles doing so, come back here and ask, but you should attach your worksheet rather than a picture, so we can help in a better way than just describing what you have to do.
