There's nothing wrong with the mark allocation for those 2 questions. For (a), 1 mark for determining the gradient and 1 for finding the correct angle. Isn't (b) worth 1 mark, like it only requires modifying the numbers to use the limit.
Re: MX2 Integration Marathon
This is what I did when I answered it in the other marathon: http://community.boredofstudies.org/attachments/14/mathematics-extension-2/30828d1409035801-hsc-2014-4u-marathon-screen-shot-2014-08-26-4.48.33-pm.png
Re: MX2 Integration Marathon
If divide top and bottom by n^2, we obtain a Riemann's sum for approximating the area beneath the curve y=1/(x^2+x+1) in the interval 0≤x≤1. Since f(x) is decreasing in that interval, B represents the sum of 'n' upper rectangles and A represents the sum of 'n' lower...