Solving differential equations using Matlab

Looking to solve the following ODE but have no idea where to start. I have y= 1.1*x + .15*Dx - 1.5*Dy with zero initial conditions at t=0. The following is what I have tried but I keep getting a warning saying that I need to reset the symengine in order to display the result but resetting the symengine doesn't seem to do anything.

>> syms x(t) y(t)

>> dsolve('y = 1.1*x + .15*Dx - 1.5*Dx', 'y(0)=0', 'x(0)=0' )

Thanks for the help

Answer 1

[Walter Roberson]

You used Dx twice instead of Dy .

The solution to your system is not unique. The general solution is

x(t) = arbitrary subject to x(0) = 0
y(t) = (int((1/30*(22*x(t)+3*(diff(x(t), t))))*exp((2/3)*t), t)+C1)*exp(-(2/3)*t)

where C1 is a constant of integration needed to provide the y(0) = 0 . The value of it will depend upon x(t) .

You can use any of a number of functions for x(t). For example, x(t) = t^2 is fine, as is x(t) = cos(t) - 1 or x(t) = exp(t) - 1 .