化简sin^2x+sin^2y-sin^2xsin^2y+cos^2xcos^2y_数学解答

化简sin^2x+sin^2y-sin^2xsin^2y+cos^2xcos^2y

人气：140 ℃　时间：2020-04-04 10:00:40

解答

sin²x+sin²y－sin²xsin²y＋cos²xcos²y
= sin²x＋sin²y-sin²xsin²y+(1－sin²x)(1－sin²y)
= sin²x＋sin²y-sin²xsin²y＋1-sin²x-sin²y+sin²xsin²y
=1