dfrac (2pi )(sqrt {3)}-|||-D. dfrac (pi )(6)
sqrt (2)pi -|||-C. dfrac (sqrt {2pi )}(4)-|||-D. dfrac (sqrt {2pi )}(8)
[ 0,dfrac (pi )(2)] D. [ -sqrt (dfrac {pi )(2)},0]
dfrac (qQ)(4pi {varepsilon )_(0)l} C. dfrac (qQ)(2pi {varepsilon )_(0)l} D. -dfr
. _(Y)(y)=dfrac (1)(2sqrt {2pi )}(e)^-dfrac (y{2)} ,gt 0-|||-bigcirc ._(Y)(y)=d
把复数=((cos dfrac {2pi )(9)+isin dfrac (2pi )(9))}^3转化为三角形式A =((cos dfrac {2pi )(9
(B) (mu ,dfrac (1)(sqrt {2pi )})-|||-(C) (mu ,dfrac (1)(2)), (D)(0,σ).
=-sqrt (2)(sin dfrac (pi )(6)+icos dfrac (pi )(6))的指数表达式为( )。A =-sqr
dfrac ({mu )_(0)I}(pi R)(dfrac (1)(2)+dfrac (pi )(6))-|||-dfrac ({mu )_(0)I}(pi
A、 dfrac (pi )(6) B、 dfrac (2pi )(3) C、 dfrac (4pi )(3) D、 dfrac (pi )(3)-|||-2、