证明(tan^2-sin^2)cot^2=sin^2_其他解答

证明(tan^2-sin^2)cot^2=sin^2

人气：416 ℃　时间：2020-05-21 01:34:59

解答

(tan^2-sin^2)cot^2
=(sin^2/cos^2-sin^2)cot^2
=sin^2(1/cos^2-1)cot^2
=sin^2(1-cos^2)/cos^2*cot^2
=[sin^2*sin^2/cos^2]*[cos^2/sin^2]
=sin^2