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[✓] Solve second order differential equation with W|A?

Posted 1 year ago
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Hello all,

First off, thank you to anyone who can respond to my query.

Can www.wolframalpha.com solve the following?

y''+0.11y'+2sin(y), y(0) = 0.15, y'(0)=0

I want to use a numeric method to find an estimate when x = 1, or find the true value, but when I type in:

"Runge-Kutta method, y''+0.11y'+2sin(y)=0, y(0) = 0.15, y'(0)=0, from 0 to 1, h = 0.2"

It seems like it doesn't know how to interpret it.

All the numeric examples I can see appear to only be first order so I wondered if that was the problem?

If it can't, how might I get around it?

Thanks,

Steve

2 Replies
Posted 1 year ago

This

WA Link

seems to work with fourth order, but the time interval that it solves over and the stepsize appears to change each time you retry the calculation. Try it a few times until it looks like it has included x=1 and the stepsize is 0.2. Clicking on "More" next to the "Stepwise Results" will show you more of the table and you should be able to find the estimate when x=1.

Posted 1 year ago

Hi Bill,

Thanks for taking the time to answer me, the time interval and step size worked perfectly for me first time so I will download the table just in case.

I was able to find the estimate at x=1 in the table as you suggested.

Thanks,

Steve

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