Hye everyone :) How do i write this equation in a correct way? Every time i compile, this error keeps coming out>> error: invalid operands of types 'double' and 'double' to binary 'operator^'

U = (180/(15*PI))*(acos(sin((-0.8333-(0.0347)*((H)/abs (H))*(abs (H)^0.5))*(PI/180))-(sin((D*PI)/180)*(sin(B*(PI/180)))))/(cos(D*(PI/180))*cos(B*(PI/180))))

thank you very much in advance :)