化简:sin2(α+π)•cos(π+α)•cos(-α-2π)tan(π+α)•sin3(π2+α)•sin(-α-2π)=______.-数学

题目简介

化简:sin2(α+π)•cos(π+α)•cos(-α-2π)tan(π+α)•sin3(π2+α)•sin(-α-2π)=______.-数学

题目详情

化简:
sin2(α+π)•cos(π+α)•cos(-α-2π)
tan(π+α)•sin3(
π
2
+α)•sin(-α-2π)
=______.
题型:填空题难度:中档来源:不详

答案

根据诱导公式及正弦余弦函数的奇偶性化简得:
sin2(α+π)•cos(π+α)•cos(-α-2π)
tan(π+α)•sin3(class="stub"π
2
+α)•sin(-α-2π)
=
(-sinα)2•(-cosα)•cosα
tanα•cos3α•(-sinα)
=
sin2α•cos2α
class="stub"sinα
cosα
cos3α•sinα 
=1
故答案为1.

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