If k, lo, r1, and r2 are constants, you can use anonymous function to calculate the expression:
k=randi(10,1,1);
lo=randi(10,1,1);
r1=randi(10,1,1);
r2=randi(10,1,1);
% theta in degree
func = @(theta) (k*lo*cotd(theta)/r1^4)+(k*lo*((cscd(theta)/r2^4)-(cotd(theta)/r1^4)))
func(25) % make sure to put values in degree, not in radians
You can write multiple values while calling the function
func([25,45,120,160])
