(2011•广安二模)若角a的终边过点P(-1,0),则sin(α+π3)等于( ) A.0 B.-12 C.32 D.-32
问题描述:
(2011•广安二模)若角a的终边过点P(-1,0),则sin(α+
)等于( )π 3
A. 0
B. -
1 2
C.
3
2
D. -
3
2
答
由角a的终边过点P(-1,0),得到α=2kπ+
,3π 2
则sin(α+
)=sin(2kπ+π 3
+3π 2
)=-sinπ 3
=-π 3
.
3
2
故选D