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Edexcel 9MA01 Maths A-level Paper 2 (Pure) 12th June 2019 - Unofficial Markscheme

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Reply 60
Original post by wajopdsjf
i got 13 tho


Yeah that's what I meant xD
Guys what do you reckon A* is out 200 so far. I think I’ve got 165 so far :frown:
Original post by RuneFreeze
Did anyone else think the sum/integral one was really badly put. Like I'm sure it wanted the integral but technically the limit is equal to zero.


Question 5?

Exactly, the sum we were given was not an infinite sum of infinitely tiny terms, but rather 5 of these infinitely tiny terms, which is 0.
Does anyone remember the differential equation for the last question?
me too
Original post by mohamadjamil03
Errrr, I accounted for both the thinking and braking distance and got 98 and a bit, so he didn't reach the puddle.
Original post by Commathingy
Question 5?

Exactly, the sum we were given was not an infinite sum of infinitely tiny terms, but rather 5 of these infinitely tiny terms, which is 0.

i just calculated the integral of sqrt(x) from x=4 to x=9 in the end, didn't know what else to do
its not equal to zero it just tends towards zero - essentially implying the trapezium rule with very very thin trapezia which is equal to the integral
Original post by Commathingy
Question 5?

Exactly, the sum we were given was not an infinite sum of infinitely tiny terms, but rather 5 of these infinitely tiny terms, which is 0.
Original post by NATHan w
Guys what do you reckon A* is out 200 so far. I think I’ve got 165 so far :frown:


By last year's boundaries, this would be an A* and people generally found this year's paper harder than last year's, so you're in a good place.
Reply 68
Original post by Xooi200
I got 22.3 years I believe, and so did other. Yourself?


nah I got 40 smt but a lot of people got 70ish
Original post by another_truffle
its not equal to zero it just tends towards zero - essentially implying the trapezium rule with very very thin trapezia which is equal to the integral


They're not wrong. The notation on Edexcel's part wasn't very good and as written it is equal to zero, but people seemed to generally know what they meant.
Could I just ask how did you guys get 70 years?? I got -12.5 years, then turned it positive
Original post by another_truffle
its not equal to zero it just tends towards zero - essentially implying the trapezium rule with very very thin trapezia which is equal to the integral


No the limit is equal to zero. It was the sum of 5 rectangles, each of which has an area in the limiting case of 0.
(edited 4 years ago)
Can u stop acting like u did bad. You know you did good but you post in here lookin for what? Praise? 165 means u think u got above 80 in the 2 papers. That’s more than enough for an a*
Original post by NATHan w
Guys what do you reckon A* is out 200 so far. I think I’ve got 165 so far :frown:
Original post by RedGiant
g(0) was 5, which is greater than 2, so 4(5) - 7 = 13


Ah sh*t
For the second question (trapeizium rule) could you use s= 0.5(u + v)t
Reply 75
That will be an A* easily, as long as you don't ruin paper 3 xD
Original post by NATHan w
Guys what do you reckon A* is out 200 so far. I think I’ve got 165 so far :frown:
Original post by Khizar Ahmed
For the second question (trapeizium rule) could you use s= 0.5(u + v)t


not constant acceleration sorry, apparently it was the trapezium rule
Original post by RuneFreeze
No the limit is equal to zero. It was the sum of 5 rectangles, each of which has an area in the limiting case of 0.


literally its an arrow towards zero - not an equal sign.... there's a difference between the two and its basically the first principles of integration
But as it used sigma notation, from 4 to 9, there are only 5 rectangles, with heights sqrt(4), sqrt(5), sqrt(6), sqrt(7), sqrt(8), sqrt(9) respectively. Each of these has a base length of dx so the total area, which is the answer we want, is the sum of these squares multiplied by dx. As a sum of these 5 sqrt terms is a normal number, we can write it as "k". We are at this point left with kdx with dx->0. This is a simple limit and is just zero. Using an integral, although it may be the wanted method, if not actually a legitimate way of working here
Original post by another_truffle
its not equal to zero it just tends towards zero - essentially implying the trapezium rule with very very thin trapezia which is equal to the integral
Original post by Khizar Ahmed
For the second question (trapeizium rule) could you use s= 0.5(u + v)t


oh crap I forgot to use the trapezium rule

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