∫x⁢(fν⁢g^ν+gν⁢f^ν)⁢ⅆ⁡x=14⁢x2⁢(2⁢fν⁢g^ν-fν-1⁢g^ν+1-fν+1⁢g^ν-1+2⁢gν⁢f^ν-gν-1⁢f^ν+1-gν+1⁢f^ν-1).