# help with a Differential Equations

• Feb 25th 2014, 10:24 PM
help with a Differential Equations
good morning every one
i had this Differential Equation in a physic problem and i need it solution so it would be great if you could help the Equation is

y'=a+cos(y)*x

where - a - is a constant

and thank you for your time
• Feb 26th 2014, 12:05 AM
romsek
Re: help with a Differential Equations
Quote:

good morning every one
i had this Differential Equation in a physic problem and i need it solution so it would be great if you could help the Equation is

y'=a+cos(y)*x

where - a - is a constant

and thank you for your time

There's no closed for solution that Mathematica could find.
I looked at numerical solutions for a in the range of -5 to 5, with initial values of -1, -0.5, 0, 0.5, 1
The solution is pretty dependent upon the value of a.
Not so much on the initial value of y(t).

In general the solutions overshoot a final value and then settle back to it but without ringing. That final value depends on a.
• Feb 26th 2014, 02:33 AM
Re: help with a Differential Equations
thanks man
but
a = 10
and y is a function of x , y(x)
• Feb 26th 2014, 04:13 AM
romsek
Re: help with a Differential Equations
Quote:

thanks man
but
a = 10
and y is a function of x , y(x)

Attachment 30252

a graph of the solution with a=10, y(0)=0
• Feb 26th 2014, 05:44 AM