sqrt (2)pi -|||-C. dfrac (sqrt {2pi )}(4)-|||-D. dfrac (sqrt {2pi )}(8)

dfrac (2pi )(sqrt {3)} D. dfrac (pi )(6)

dfrac (2pi )(sqrt {3)}-|||-D. dfrac (pi )(6)

sqrt (2)pi :2 C. sqrt (2)pi :4 D. sqrt (2)pi :8

. _(Y)(y)=dfrac (1)(2sqrt {2pi )}(e)^-dfrac (y{2)} ,gt 0-|||-bigcirc ._(Y)(y)=d

(B) (mu ,dfrac (1)(sqrt {2pi )})-|||-(C) (mu ,dfrac (1)(2)), (D)(0,σ).

[ 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

=dfrac (T)(2pi )leqslant [ t] =dfrac ([ O] )(2);-|||-_(2)(A)_(1)+dfrac ({M)_(y)}

dfrac (pi )(4) C. dfrac (pi )(2) D.π

dfrac (1)(2)pi (R)^2E-|||-D. sqrt (2)(R)^2E-|||-E. dfrac (pi {R)^2E}(sqrt {2)}