y=dsolve('D2y=(-9.8sin(y))','t')用matlab怎么解出y的轨迹?就是y对t的二阶导加上9.8siny=0

y=dsolve('D2y=(-9.8sin(y))','t')用matlab怎么解出y的轨迹?就是y对t的二阶导加上9.8siny=0 matlab 符号常微分y=dsolve('D2y-100*(1-y^2)*Dy=-y','y(0)=2,Dy(0)=0','x')哪里错了? matlab（1-x）*y''=0.2*sqrt(1+y'^2) 输入y=dsolve('(1-x)*D2y-0.2*sqrt(1+(Dy)^2)=0', 用MATLAB求微分方程,并画出图形解y=dsolve('D3y=D2y-Dy-y+t^2','y(0)=0','Dy(0)=1','D2y(0)=-1')这样解了之后怎么画出图形啊! matlab解不了这个简单的微分方程dequ='D2y=-GM/(y^2)'y=dsolve(dequ,'y(0)=R0','t')运行结果：Warning:Explicit solution could not be found.> In dsolve at 101怎么回事? matlab求解常微分y=dsolve('D3y-3*D2y-Dy*y=0','y(0)=1 Dy(0)=-1 D2y(0)=0','t')错误如下? Error using ==> dsolveat offset 84, `=` unexpectedError in ==> fun1 at 1y=dsolve('D3y-3*D2y-Dy*y=0','y(0)=1 Dy(0)=-1 D2y(0)=0','t')求大神啊 如何解此常微分方程：m*y''=-k*(y')^2+mg,y(0)=0,y'(0)=0其中m,g是常量.忘记说了，k也是常量。还有，最好用MATLAB来解，我的程序是S=dsolve('D2y=(-k/m)*(Dy)^2+g','y(0)=0,Dy(0)=0') 用matlab解微分方程y=dsolve('D2y+Dy-2y=2x','y(0)=0,Dy(0)=1','x')为什么输出结果是ans =1 用matlab解题出现y = [ empty sym ] 为什么y=dsolve('2*x*D2y=sqrt(1+(Dy)^2)','y(100)=0,Dy(100)=0','x'),我以前算的就是这个啊这次为什么不行了 用matlab解：y=dsolve('D2y+exp(-t)*Dy-sin(sqrt(t))*y=exp(-t)*sin(sqrt(t))','y(0)=1,Dy(0)=-2','t') matlab动画模拟小球滑落我想问下关于matlab做一个小球从确定一个点沿着确定的轨道滑落到另外一个确定的点,关于时间做一个动图.我们已经知道微分方程肯定满足s=dsolve('D2x+D2y=20*y');轨道方程 MATLAB解微分方程 ：a=105.52 b=0.059 dsolve('D2y+2783.83*(1-2*b*cos(a*t))*y=0','y(0)=1','Dy(0)=0','没有解析解,请问数值解怎 么求 matlab中想求出y=dsolve('D2y+y=sin(t) * cos(30)','t'),再画图,该怎么办?会出现Conversion to double from sym is not possible. 怎么用matlab画微分方程图象RT.大神求这个函数dsolve('D2y+9*y+3*y*exp(t)=0','t')怎么直接用matlab画图象,程序是什么, 利用Matlab的dsolve命令解微分方程答案为什么不对?我想求解y''+4y'+3=0这个方程,我利用这个命令dsolve('D2y+4*Dy+3=0','y(0)=5','Dy(0)=-7'),25/(16*exp(4*t)) - (3*t)/4 + 55/16 ,但很明显这方程的解是 exp(-3*t)+4*exp(-t) 用ODE函数解微分方程和用dsolve有什么区别?微分方程为：y''+4*y'+29y=0,y(0)=0,y'(0)=15这是用dsolvey = dsolve('D2y+4*Dy+29*y=0','y(0)=0,Dy(0)=15','x');x = linspace(-3,3,100);yd = eval(y);plot(x,yd)这是用ODE函数：function dy=v matlab dsolve 这个式子哪出错了?y=dsolve('((D2y*Dx-Dy*D2x)/(Dx)^3)*(1-x)-0.2*sqart(1+(Dy/Dx)^2)=0','y(0)=0,Dy(0)/Dx(0)=0','t') 就是要解——（1-x）*y''=0.2*sqart(1+y'^2)初始条件：y（0）=0 y’（0）=0 （这里y都是对x求导 matlab求解微分方程的通解问题解某微分方程：x^2*D2y+x*Dy+(x^2-1/2)*y=0,初值：y(pi/2)=2,Dy(pi/2)=-2/pi,书本标准答案为：ans=2^(1/2)*pi*^(1/2)/x^(1/2)*sin(x)；但我运行：dsolve('x^2*D2y+x*Dy+(x^2-1/2)*y=0','y(pi/2)=2,Dy(p