Differentiation test

Everyone did well on the main question in today's test - a really strong performance on this question.

The differentiating from first principles was a little dodgy though.
I have annotated a typical marking scheme for this, so you can see where you would pick up blunders B(-3), slips S(-1) or misreadings M(-1). Nobody made the dreaded "worthless" W(0) grade.

The main issue is that many students leave out the left hand side (abbreviated as LHS). The process of differentiation only makes sense if you include the left hand side. In today's test, several students wrote things like 4x - x^2 = 4 - 2x which doesn't make any sense.

Read through the this marking scheme (taken from the 2005 exam). We will go through it on Monday and I will get everyone to mark their own first principles answer according to this outline.