新编人教版精品教学资料1sin 95cos 175的值为()Asin 5Bcos 5来源:数理化网C0 D2sin 5解析：选C.原式cos 5cos 50.2下列与sin()的值相等的式子为()Asin() Bcos()来源:www.shulihua.netCcos() Dsin()解析：选D.sin()cos ，经验证知只有sin()cos .3若sin()cos()m，则cos()2sin(6)()A B.C. D解析：选D.sin()cos()sin sin m，sin .而cos()2sin(6)sin 2sin 3sin .4已知f(x)sin x，下列式子中成立的是()Af(x)sin x Bf(2x)sin x来源:www.shulihua.netwww.shulihua.netCf(x)cos x Df(x)f(x)解析：选C.f(x)sin(x)sin x，f(2x)sin(2x)sin x，f(x)sin(x)sin(x)cos x，f(x)sin(x)sin xf(x)，来源:www.shulihua.net故选C.5已知为锐角，2tan()3cos()50，tan()6sin()10，则sin 的值是()A. B.C. D.解析：选C.由已知可得2tan 3sin 50，tan 6sin 10.tan 3，又tan ，9，sin2，为锐角，sin ，故选C.6已知cos()，且|，则tan _.解析：cos()sin .sin ，又|0，cos 0，原式1.答案：19化简：(1)sin()cos()；(2)sin(5)cos()sin()cos(2)解：(1)原式sin()(sin )sin()(sin )(cos )(sin )cos2.(2)原式sin()cos()cos cos(2)sin()cos()cos cos(2)sin()sin cos cos sin2cos21.10已知sin(x)，求sin2(x)sin(x)的值来源:www.shulihua.net解：sin2(x)sin(x)sin2(x)sin(x)cos2(x)sin(x)1sin2(x)sin(x)1.