• 2022-07-23 问题

    下列Matlab代码,能求解微分方程 y'(t) = 2*t , y(0) = 1的是( ) A: tspan = [0 5];<br> y0 = 0;<br> [t,y] = ode45(@(t,y) 2*t, tspan, y0); B: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*t, tspan, y0); C: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*y, tspan, y0); D: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*t*y, tspan, y0);

    下列Matlab代码,能求解微分方程 y'(t) = 2*t , y(0) = 1的是( ) A: tspan = [0 5];<br> y0 = 0;<br> [t,y] = ode45(@(t,y) 2*t, tspan, y0); B: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*t, tspan, y0); C: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*y, tspan, y0); D: tspan = [0 5];<br>y0 = 1;<br>[t,y] = ode45(@(t,y) 2*t*y, tspan, y0);

  • 2021-04-14 问题

    下列程序运行后,看到的图形( ?????)。 ?????t=0:pi/6:2*pi;[x,y,z]=cylinder(t, 6);surf(x,y,z)view(0,90);axis equal

    下列程序运行后,看到的图形( ?????)。 ?????t=0:pi/6:2*pi;[x,y,z]=cylinder(t, 6);surf(x,y,z)view(0,90);axis equal

  • 2021-04-14 问题

    如何用Maltab求解 y'(t) = 2*t , y(0) = 0?

    如何用Maltab求解 y'(t) = 2*t , y(0) = 0?

  • 2022-07-23 问题

    如下命令中不能实现如下微分方程组[img=327x203]17e443a5d83ce02.png[/img],在初值条件[img=172x112]17e443a5e2ead01.png[/img]下的特解求解的是: A: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0', 't') B: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1, y(0)=0', 't') C: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0') D: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0', 'x')

    如下命令中不能实现如下微分方程组[img=327x203]17e443a5d83ce02.png[/img],在初值条件[img=172x112]17e443a5e2ead01.png[/img]下的特解求解的是: A: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0', 't') B: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1, y(0)=0', 't') C: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0') D: [x,y] = dsolve('Dx+5*x+y = exp(t)', 'Dy-x-3*y=0', 'x(0)=1', 'y(0)=0', 'x')

  • 2022-06-12 问题

    以下哪一项属于二阶齐次线性差分方程? A: y(t+2)-3*y(t+1)+y(t)=0 B: y(t+2)-3*y(t+1)+y(t)=2 C: (y(t+2))^2-3*y(t+1)+y(t)=0 D: y(t+1)+3*y(t)=0

    以下哪一项属于二阶齐次线性差分方程? A: y(t+2)-3*y(t+1)+y(t)=0 B: y(t+2)-3*y(t+1)+y(t)=2 C: (y(t+2))^2-3*y(t+1)+y(t)=0 D: y(t+1)+3*y(t)=0

  • 2021-04-14 问题

    \(y''+4y'+3y=e^{-t}\),\(y(0)=y'(0)=1\)的解为\(y(t)=\frac{1}{4}[(7+2t)e^{-t}-3e^{-3t}]\) ( )

    \(y''+4y'+3y=e^{-t}\),\(y(0)=y'(0)=1\)的解为\(y(t)=\frac{1}{4}[(7+2t)e^{-t}-3e^{-3t}]\) ( )

  • 2021-04-14 问题

    【计算题】描述某系统的微分方程为 y”(t) + 5y’(t) + 6y(t) = f(t) 求 当 f(t) = 2e-t , t ≥ 0 ; y(0)=2 , y ’ (0)= -1 时的全解; (10.0分)

    【计算题】描述某系统的微分方程为 y”(t) + 5y’(t) + 6y(t) = f(t) 求 当 f(t) = 2e-t , t ≥ 0 ; y(0)=2 , y ’ (0)= -1 时的全解; (10.0分)

  • 2021-04-14 问题

    def fun(x,y): global x,y t=x x=y y=t x=0 y=1 fun(x,y) print(x,y) 结果是 1 0

    def fun(x,y): global x,y t=x x=y y=t x=0 y=1 fun(x,y) print(x,y) 结果是 1 0

  • 2022-07-01 问题

    int x = 1, y =6;  A:  x = 6 y = 0 B:  x = 7 y = 0 C:  x = 6 y = -1 D:  x = 7 y = -1 E:  Compilation fails.

    int x = 1, y =6;  A:  x = 6 y = 0 B:  x = 7 y = 0 C:  x = 6 y = -1 D:  x = 7 y = -1 E:  Compilation fails.

  • 2022-06-16 问题

    已知X=1,Y=2,T=0 经程序段X=T:T=Y:Y=T 赋值后 X,Y 值分别为()

    已知X=1,Y=2,T=0 经程序段X=T:T=Y:Y=T 赋值后 X,Y 值分别为()

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