Feedback on Paper 2 Mini-mock

Overall the results on paper 2 were lower than for paper 1 ... what is it about co-ordinate geometry?

Going through the questions one by one :

The trigonometry question required you to use the table (that I wrote up on the board) that is in the maths tables book. There you see that the angle whose tan = 1 is the angle π/4 i.e. 45º
Then you go to your CAST circle and count 45º as your reference angle in each of the 2 quadrants where Tans are negative.

The geometry part a) question was well answered in general - just check that you are looking at the correct angles e.g. |<opq|

The co-ordinate geometry question went a little haywire for some. In part (i) you were told that the point (-1,h) was on the line 3x - 4y + 7 = 0.
This means that 3(-1) - 4(h) + 7 must be = 0 so write it as
3(-1) - 4(h) + 7 = 0
and solve. Then you get the full co-ordinates of this point - (-1, 1).
Part (ii) involved simultaneous equations. Note that a simultaneous equations don't necessarily always work out evenly, but simultaneous equations in co-ordinate geometry almost always will.
Part (iii) said to show the 3 points and two lines on a coordinate plane. If you are asked to do this, make sure that you show all the points and lines you are asked for. Some students joined p and q, forming a triangle. This wasn't part of the question. When you are drawing a coordinated plane, use a pencil and make sure that the scales on the X- and Y-axes are even and equal.
Part (iv) required you to find the slopes of each line and prove that their product was -1.

The theorem was poorly answered. Nobody got full marks. Many didn't even attempt it. Don't leave it blank in your exam. You get attempt marks (6 out of 20) for just demonstrating that you get the gist of it. As I said when we studied this theorem before the mocks, the trickiest part is figuring out which facts you are allowed to assume (in this case it is that a line which is parallel to one side of a triangle divides the other two sides in the same ratio) and facts which you have to establish (that the line you constructed is parallel, and you do this by proving SAS congruence).
No matter how elusive the subtleties of a theorem may be, there is no excuse for not writing down, Given: To prove: Construction: and Proof: along with a diagram.

The question on volume of a cone was reasonably well attempted - but there was one glaring recurring error.
The 2nd cone had height = 2x and radius = 1.5x
So the total volume was
1/3 π r² h
= 1/3 π(2x)²(1.5x)
= 1/3 π4x²(1.5x)
= 1/3 π6x³
= 2x³π
Even in the middle of the perimeter area and volume question, you need to know your algebra.

Finally the statistics question was pretty well answered. Use a pencil for the graph, make the scales even and mark the points of your graph carefully - some students are getting a bit sloppy here, so don't get into bad habits.

We will go over these and other Paper 2 issues tomorrow. Line up any questions you may have for our last 2 classes.