-dfrac (3pi )(4) 是第二象限角.

1357.已知 tan x=1, in (dfrac (pi )(2),dfrac (3pi )(2)), 则 =-|||-

5、两向量a,b所在直线夹角为 π/4 lt 0, 那么下列说法正确的是 ()-|||-A、a,b夹角 dfrac (pi )(4) B、a,b夹角 dfrac

(B) pi +dfrac (4)(3) (C) pi +2 . (D) pi +dfrac (8)(3)

dfrac (pi )(3)B . dfrac (pi )(3)C . dfrac (pi )(3)D . dfrac (pi )(3)[单选题]复数1+i对应

求函数 =x(y)^2+(z)^3-xyz 在点(1,1,2)处沿方向角为-|||-alpha =dfrac (pi )(3), beta =dfrac (pi

当theta =dfrac (pi )(4)时，theta =dfrac (pi )(4)____;当theta =dfrac (pi )(4)时，theta

( (int )_(dfrac {pi )(4)}^dfrac (pi {3)}dfrac (x)({sin )^2x}dx ;

[单选题]设角a是第二象限角，则A．AB．BC．CD．D

当theta =dfrac (pi )(3)时，theta =dfrac (pi )(3)______，theta =dfrac (pi )(3)______，

当 theta =dfrac (pi )(3) 时，theta =dfrac (pi )(3)________ ，theta =dfrac (pi )(3)__