As further maths discussion

Can anyone remember any answers they got for the as further maths Edexcel today

I got 1800 times pi for the volumes of revolution question and said it was an overestimate as the surface is not likely to be smooth ? i have no idea if that’s right though i found the paper quite hard

i got about 5700kg for the volumes question, in vectors i think the point B was (5,1,1) or something similar, in the z^10 question i think i got a=(3sqrt3)/2 b=-3/2. don’t remember much else and honestly idk if i got any of these right 😭

I remember getting these ! For that matrices one where it said what the student did wrong i put that they did AB instead of BA and that AB is not the same as BA so it should have been the transformation matrix multiplied by the other one

i got about 5700kg for the volumes question, in vectors i think the point B was (5,1,1) or something similar, in the z^10 question i think i got a=(3sqrt3)/2 b=-3/2. don’t remember much else and honestly idk if i got any of these right 😭

Complex numbers - u just multiply by complex conjugate on denominator, and get 1/2.

Argand diagrams - there were 2 questions. One had a line with y = sqrt(3)x - 2 sqrt(3) and another one which was y = (sqrt(3)/3)x + sqrt 3, I think. Either way, x turns out to be 7/2 or 3.5 and you can solve for y easily and put into a + bi form. The other one had a nice question with the mod to the power of 10 and arg to the power of 10. Rooting the mod to power 10 got 3 and args work like logs, so you can divide by 10 and get arg was minus pi / 6.

Series - n was 4 I think and the last part was a fun question where u sub say 999 = 2x -1 and upper bound is 500 and 101 = 2x -1 so lower bound was 51. It gave a 9 digit answer once solved.

Roots - There was an easy 5 marker for quartic where you just sub in w = 3z+1 or whatever it was, rearrange for z and multiply out the brackets. I think it was something like w^4 + 4w^3 + 51w^2 + something - 3000ish. Also the last question had roots. You had to notice the the sum of the roots was 0 as there was no x^2 term, so beta was equal to 4 alpha. Then multiply the the roots together and equate it to the term in the question. I think n was -63.

Volumes - was already discussed above and was 1800 pi, but the reasons for the 1 markers were hard to get

Matrix - was the first question as a 4 marker. It was mainly a joke with simple addition and subtraction. Another question where you prove a matrix was non-singular. Take the determinant and obtain a quadratic. You can take the discriminant and as it was below 0, there are no solutions. Alternatively, you could use completing the square and use a sketch.

Linear transformations - fun question, there were 2 methods. The most common one was to multiply the transformation by the coordinates given and obtain the new coordinates in terms of a. Then find the distance between the new and old coordinates and use pythagoras to equate this to root 58. Square both sides and solve a quadratic. I think answer was 31/5 and 3 for a. An alternate method was taking the determinant of the matrix = -3, so area scale factor was 3 so a line scale factor was root 3. Multiply this by the distance between the original coordinates using pythagoras and equate it to root 58, and solve. Another question where the student made the error of doing AB instead of BA and we had to annoyingly multiply two 3x3 matrices

Surprisingly no proof by induction this year. I think thats a first.

Vectors was easier than most years. The main 6 marker had 4 bullet points that needed to be satisfied. You solve and get 14x^2 = 14. If x = 1, then one of the coordinates was negative, but the question said it had to be positive so x = -1 and answer was (1 , 1 , 5)

Overall , I feel like this was easier than most of the past papers. I've seen some horrendous chimpanzee matrices questions so compared to that, it was doable. I hope you guys feel like it went well overall.

I got 5200 when rounded so im not sure when I messed up. I made x^2 the subject so integrated 2-y between 0 and sqrt2 which I thing was the right thing to do? Then just multiplied the answer by the density and I think that came out to 5169. Would someone mind pointing out where I went wrong

Was there a proof by induction question or am I tripping??