<img src="http://edu-image.nosdn.127.net/E6A0628104FCB0F521FBF2AAAC7F1968.png?imageView&thumbnail=890x0&quality=100" style="width: 558px; height: 33px;" />? syms xy=log(1/x*x+exp(x))+sin(1-x^2)dy/dx=diff(y,x)|syms xy=log(1/x/x+exp(x))+sin(1-x^2)dydx=diff(y,x)|syms xy=log(1/x/x+exp(x))+sin(1-x)^2dydx=diff(y,x)|syms xy=log(1/x/x+exp^x)+sin(1-x^2)dydx=diff(y,x)

执行下面命令后，则y(x)=( ) syms f(x) f(x)=3*x^2+4*x-5; y=subs(f,2)

设\(z = f(x,y)\)，\(x = \sin t\)，\(y = {t^3}\)，则全导数\( { { dz} \over {dt}} = \) A: \({f'_x} \sin t+ 3{t^2}{f'_y}\) B: \({f'_x} \cos t+ {t^2}{f'_y}\) C: \({f'_x} \cos t+ 3{t^2}{f'_y}\) D: \({f'_y} \cos t+ 3{t^2}{f'_x}\)

‏根据方程F(x,y,z)=0求[img=20x44]1802e4e0282af80.png[/img]，应使用命令‏ A: -diff(F,x)/diff(F,y) B: diff(F,x)/diff(F,y) C: -diff(F,y)/diff(F,x) D: diff(F,y)/diff(F,x)

已知“syms x y z t a b; x=a*cos(t); y=a*sin(t); z=3*t; dx=diff(x,'t'); dy=diff(y,'t'); dz=diff(z,'t'); f=y*dx-x*dy+(x+y+z)*dz; t1=0; t2=2*pi; W=int(f,t,t1,t2)”,则正确的说法是【】