How to convert this ODE to a standard form

oxxiissiixxo
Messages
27
Reaction score
0

Homework Statement



Convert to standard form ODE system y0 = f(t, y):
t^2y'' + sin(y') + 2y − 1 = 0

the goal is to reduce the equation above to be a first order ode.

Homework Equations


The Attempt at a Solution



I tried to introduced a new variable but the sin(y') seems tricky.
 
Last edited:
Physics news on Phys.org
What is y0? Also, what is y differentiated with respect to.
 
oxxiissiixxo said:

Homework Statement



Convert to standard form ODE system[/color] y0 = f(t, y):
t^2y'' + sin(y') + 2y − 1 = 0

the goal is to reduce the equation above to be a first order ode. Above you said "system".[/color]

The Attempt at a Solution


I tried to introduced a new variable but the sin(y') seems tricky.
I'll assume the derivatives are with respect to t. If we let x(t) = y'(t), then the equation becomes (t^2)x' + sin(x) + 2y - 1 =0, which can be solved for x' in terms of t, x, y. In this way we obtain a system of the form [y', x'] = [f(t,x,y), g(t,x,y)].
 
Last edited:
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
Back
Top