1.求解下歹刂方程:-|||-(1) '=dfrac (1)(2x') (这里 '=dfrac (dx)(dt) ,''=dfrac ({d)^2x}(d{t)^2} ,以下同);

)int dfrac (1)({cos )^2x(sin )^2x}dx.

(6) () =dfrac (1)(sqrt {1-{x)^2}} int dfrac (1)(sqrt {1-{x)^2}}dx=() .

2-3 用拉氏变换法解下列微分方程:-|||-(1) dfrac ({d)^2x(t)}(d{t)^2}+6dfrac (dx(t))(dt)+8x(t)=1,

(B)当 (x)lt 0 时, (dfrac (1)(2))lt 0.-|||-(C)当 (x)gt 0 时, (dfrac (1)(2))lt 0. (D)当

下列求导结果正确的是A (x+dfrac (1)(x))=1-dfrac (1)({x)^2}B (x+dfrac (1)(x))=1-dfrac (1)

dfrac (1)(3)f(x) C. -3f(x) D. -dfrac (1)(3)f(x)

已知f(x)=(2x)/(sqrt (1-{x)^2)}，则(df(sqrt (1-{x)^2)})/(dx)=(,,,,,)A、-2；B、-dfrac(2x)

[题目]若 (dfrac (1)(x))=x, 则 (x)= ()-|||-A、 dfrac (1)(x)-|||-B、 dfrac (1)({x)^2}-||

1.求下列微分方程的通解:-|||-(1) dfrac (dy)(dx)+y=(e)^-x ;-|||-(2) +y=(x)^2+3x+2;-|||-(3) +

1.求下列微分方程的通解:-|||-(1) dfrac (dy)(dx)+y=(e)^-x =-|||-(2) +y=(x)^2+3x+2 =-|||-(3)