How to solve ODE y'' - 4y' + y - x = 0 using rk4?
How to solve ODE y''+y''-4y'+x = 0 using rk4?
I tryed
# w = y''
# z = y'
var('x, w, z')
desolve_system_rk4( [w , 4*z + x] , [w,z] , ics = [0,1,0], ivar = x, end_points = 10, step = 0.1)
But does no work correty :(
The doc is here http://doc.sagemath.org/html/en/refer...
I got a way to solve the differential equation. If wrong please correct;)
To solve this differential equation we must first make a variable substitution to reduce the differential equation for a first order and thus create a system of ODEs. variable change:
w1 = y w2 = y w3 = y '
Thus, deriving the above variables, we have a system of equations of the form:
w1 '= w2 w2 '= f (x, w1, w2) = 4 * w2 + x
desolve_system_rk4([w2, 4*w2 + x ],[w1 , w2], ics = [0,1,0],ivar = x, step = 0.1, end_points = 2)
Asked: 2016-09-06 03:29:59 +0200
Seen: 398 times
Last updated: Sep 06 '16
This looks like homework. If you want some help, you should ask more precise questions related to your research in solving those exercises, especially where you are locked.