函数，则tanφ=_____________. 
函数，则tanφ=_____________. 答案：
-2 【解析】据题意可得：f(x)+f′(x)=sin(2x+)+2cos(2x+
)为奇函数,由奇函数定义可得：sin(-2x+
)+2cos(-2x+
)=-[sin(2x+
)+2cos(2x+
)]整理得：cos2x(2cos
+sin
)=0,故必有2cos
+sin
=0即tan
=-2.