问题
填空题
已知:sin(x+
|
答案
∵sin(x+
)=π 6
,1 4
∴cos2(x+
)=1-sin2(x+π 6
)=π 6
,15 16
则sin(
+x)+cos2(7π 6
-x)5π 6
=sin[π+(x+
)]+cos2[π-(x+π 6
)]π 6
=-sin(x+
)+cos2(x+π 6
)π 6
=-
+1 4 15 16
=
.7 8
故答案为:7 8