若函数sin α-cos α=-(0<α<
),则α属于( )
(A)(0,) (B)(
,
)
(C)(,
) (D)(
,
)
若函数sin α-cos α=-(0<α<
),则α属于( )
(A)(0,) (B)(
,
)
(C)(,
) (D)(
,
)
B解析:sin α-cos α=sin(α-
)=-
,
sin(α-)=-
,由-
<-
<0,
因为0<α<,
所以-<α-
<0,即
<α<
,