tan^2a =2tan^2b+1 求证 cos2a +sin^2b=0需要详解._数学解答

tan^2a =2tan^2b+1 求证 cos2a +sin^2b=0
需要详解.

人气：394 ℃　时间：2020-01-30 21:46:46

解答

tan^2a +1=2（tan^2b+1) 所以1/cos^2a=2/ cos^2b
2cos^2a=cos^2b=1-sin^2b
1+cos2a=1-sin^2b cos2a +sin^2b=0