已知角α的终边过点(3,-4),则sinα=______cos(π+α)=______.-数学

题目简介

已知角α的终边过点(3,-4),则sinα=______cos(π+α)=______.-数学

题目详情

已知角α的终边过点(3,-4),则sinα=______cos(π+α)=______.
题型:填空题难度:偏易来源:不详

答案

∵角α的终边过点(3,-4),∴x=3,y=-4,r=5,∴sinα=class="stub"y
r
=-class="stub"4
5

∵cos(π+α)=-cosα      cosα=class="stub"x
r
=class="stub"3
5

∴cos(π+α)=-class="stub"3
5

故答案为:-class="stub"4
5
,-class="stub"3
5

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