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# can someone check my graph please? watch

1. Could somebody please have a look at my graph and tell me whether it is ok to demonstrate convergence? As in is everything clear etc?

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2. according to the maths mod sitting next to me...she has no idea
3. I don't think it's possible to comment without a lot more context. As it stands (without the context), I wouldn't be pleased with it as an examiner, because it doesn't actually give enough information to know what's going on. (What's N, what's M, etc.)
4. Thank you for the reply, and sorry - stupid of me not to realise context would be needed. I have attached the relevant rabulated data in this post.

I'm basically using the Gauss quadrature rule, to approximate the integral for x^1/2.

For this I have used a number of points, n, within the rule as 1, 2 and 5. M is the number of sections the interval is split up into, i.e:

However there are two things I'm unsure about.

Firstly for N = 2 and 5, only 5 and 1 approximations respectively are needed to get to 6.d.p of the exact solution. So for these I have only plotted those points, however would it be preferable to show further approximations, even if they are all on the exact solution line?

And secondly I'm unsure whether using a loglog graph is the right approach, this is what we have been advised to use but would a semi-log graph not be better?
Attached Images

5. I don't know for certain, but I think y-axis should be "log(approximation error)" not log(approximation). I'd just put M on the x-axis as well (not log M)
6. Thank you so much David, that makes a lot more sense.

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Updated: February 4, 2010
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