sin^4x cos^2x+cos^4x sin^2 x=sin^2x*cot^2x 怎么得来sin^4x cos^2x+cos^_数学解答

sin^4x cos^2x+cos^4x sin^2 x=sin^2x*cot^2x 怎么得来
sin^4x cos^2x+cos^4x sin^2 x=sin^2x*cot^2x 怎么得来

人气：469 ℃　时间：2020-06-03 00:56:33

解答

原式等于 sin^2(sin^2+cos^2)+cos^2 = sin^2*(1)+cos^2 = sin^2+cos^2 = 1