Expression 6: "I" Subscript, "m" , Baseline equals StartFraction, theta Subscript, "z" , Baseline Over pi , EndFraction Start integral from 0 to pi , end integral, StartFraction, left parenthesis, left parenthesis, 1 minus "u" cot left parenthesis, "u" , right parenthesis , right parenthesis squared plus "u" squared , right parenthesis Over left parenthesis, "u" csc left parenthesis, "u" , right parenthesis "e" Superscript, negative "u" cot left parenthesis, "u" , right parenthesis , Baseline minus ln left parenthesis, "r" Subscript, "z" , Baseline , right parenthesis , right parenthesis squared plus theta squared , EndFraction "d" "u"Im=θzπ∫π01−ucotu2+u2ucscue−ucotu−lnrz2+θ2zdu