## Visitor's Comments

## Visitors' Comments on Tutorial: ODE

We have 5 comments on this tutorial

Error Report > Runge-Kutta Excel Tutorial (date: 2010-07-22)

By Marc Couture

I was quite surprised to see that all four numerical methods gave nearly the same values, while the exact solution was off by as much as 10% for most of the interval of the graph. First I thought the divergence near the end was the explanation, but the discrepancy started well before that point. The explanation is much more simple : the formula for the exact solution erroneously puts the value of x out of the square root. The right formula is : =SQRT( (1-2*LN(A11))/A11) instead of : =SQRT( 1-2*LN(A11))/A11 as it is in the comparison sheet. The discrepancy all but disappear. You had me work a lot on this one, but it made for a good review of my algebra.

Answer > Correction (date: 2010-07-23)

By Kardi

Dear Marc, Thanks for the correction. I have fixed the tutorial as well as the MS Excel file.

Question > runge kotta by using excel (date: 2010-10-18)

By m.elsadi

dy/dt=(x-y)^2 y(0)= 0.5 h= 0.025

Others > ORDINARY DIFFERENTIAL EQUATIONS (date: 2010-12-09)

By Ngwana titus

HOW CAN WE PROVE THE EXISTENCE AND UNIQUENESS OF THE SOLUTION OF AN ORDINARY DIFFERENTIAL EQUATION

> (date: )

By