化简sin^2(a+π)Xcos(π+a)Xcot(-a-2π)/tan(π+a)Xcos^3(-a-π)

问题描述:

化简sin^2(a+π)Xcos(π+a)Xcot(-a-2π)/tan(π+a)Xcos^3(-a-π)

sin^2(a+π)Xcos(π+a)Xcot(-a-2π)/tan(π+a)Xcos^3(-a-π)
=sin^2a(-cosa)(-cota)/tana(-cos^3a)
=-sinacos^2a/sinacos^2a
=-1