Edexcel AS Maths Paper 1 8MA0 Unofficial Markscheme 2019

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threethreethree
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1. a) find m when both lines are perpendicular, m=2
b)find x coordinate of intercepts (x=-5/2)

2. two equations to solve First was a=1/4 and 0?
second was definitely ±√2

Forgot the order so here are some of my answers:

Question on circles (centre of 2,-4) and radius of √28
the line x=k intersected at a tangent, find exact values of k, k=±√2
part c) was 2±2√7 or something like that

Queston on factorisation:
a) Prove (x-4) is a factor
b) prove the curve has two distinct roots (got x-4 as a repeated root) and -3/2 as the other root
c) Suggest the number of roots the graph f(x) - 2 had, should be three root as graph is translated by vector
(0, -2)

d)Find the value of k when f(x+k) crosses the orgin got k=4 which translated 4 to the left, or k=-3/2 which moves it 1.5 to the right

Question on binomial expansion:

a) First three terms of (2+3/4x)6 i think
b) Explain how you would use your answer to approximate (1.925)6

Question on trig:
a) Show that x = 2√3 when the area of the triangle is 18
b) Second question, find the length of AC, which was √84, simplifies to 2√21

Other trig question:
a) Had to show that the trig identity (10sin2(x) - 7cos(x) + 2) / (3 + 2cos(x)) = 4 - 5cos(x)

b) solve to get tan=-5/3. Solutions are 301 and 121 degrees in the range 0≤x<360

Question on quadratics with tin as a model of a quadratic
a) Find the value when n=1
b) State the max. amount of tin they could mine
c) Careful here. Asked for the amount mined in 2023, not amount up to 2023. So you find the amount up to 2024 and subtract from the amount up to 2023. Total was like around 100 tonnes.
d) Limitation of the model

Question on definite integrals:
Had to find the x- coordinate for when x is a minimum. X=4
You then had to use this value and x=0 as your limits to differentiate the curve to get 256/3

Question on linear modelling about trees and their height and time
a) Find the relationship between H and t

H=0.31t+1.42

b) The original height was 140 cm = 1.4m, comment on the suitability of the model


Proof:
prove n³+2 is not divisble by 8.

I proved it by counter example and when n=2n (an even number) and when n=(2n+1) an odd number and got an expression that was not wholly divisible by 8.

The proof asked for all n ∈ Z+, someone on here said you had to use (2n)² and (2n+1)² for your values of n to ensure they meet the criterion.

Question on graphs:
sketch a graph of k²/x + 1, stating asymptote equation.
Asymptote at y=1

Question on exponentials
a) initial value was like 5700+2300 = 8000
part b differential the exponent to get what they asked
part c, find the time when it is valued at £500, got 8 years 3 months
d) limitation of the model

Last question on vectors:
a) state what is meant by non-zero or something to that extent

b)

|a + b| = |a| + |b|

m = |6| and |m-n|=3 and the angle between them is 30, had to find the angle between |m| and |n|

I got 15 degrees using the sin rule, however some people got an angle of 135, which is 180-(15+30)
Last edited by threethreethree; 1 year ago
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itskxmil
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For the circle question: the k values were 2+/-(2root7)
(Original post by ak113)
1. a)find m when both lines are perpendicular, m=2
b)find x coordinate of intercepts (x=-5/2)

2. two equations to solve First was a=1/4?
second was definitely ±√2

Forgot the order so here are some of my answers:

Question on circles (centre of 2,-4) and radius of √28
the line x=k intersected at a tangent, find exact values of k, k=±√2
part c) was 2±2√7 or something like that

Queston on factorisation:
Prove (x-4) is a factor
prove the curve has two distinct roots (got x-4 as a repeated root) and -3/2 as the other root
Suggest the number of roots the graph f(x) +2 had, should be one root as graph is translated by vector (0, 2)
Find the value of k when f(x+k) crosses the orgin

Question on quadratics with tin as a model of a quadratic
Find the value when n=1 for part a and n=4 for part c
State the max amount of tin they could mine,


Question on exponentials, initial value was like 5700+2300 = 8000
part b differential the exponent to get what they asked
part c, find the time when it is valued at £500, got 8 years 3 months

Last question on vectors I got 15 degrees using the sin rule, however some people an angle of 135, which is 180-(15+30)
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itskxmil
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For the cubic graph, the graph moved 2 down so there were 3 roots
(Original post by ak113)
1. a)find m when both lines are perpendicular, m=2
b)find x coordinate of intercepts (x=-5/2)

2. two equations to solve First was a=1/4?
second was definitely ±√2

Forgot the order so here are some of my answers:

Question on circles (centre of 2,-4) and radius of √28
the line x=k intersected at a tangent, find exact values of k, k=±√2
part c) was 2±2√7 or something like that

Queston on factorisation:
Prove (x-4) is a factor
prove the curve has two distinct roots (got x-4 as a repeated root) and -3/2 as the other root
Suggest the number of roots the graph f(x) +2 had, should be one root as graph is translated by vector (0, 2)
Find the value of k when f(x+k) crosses the orgin

Question on quadratics with tin as a model of a quadratic
Find the value when n=1 for part a and n=4 for part c
State the max amount of tin they could mine,


Question on exponentials, initial value was like 5700+2300 = 8000
part b differential the exponent to get what they asked
part c, find the time when it is valued at £500, got 8 years 3 months

Last question on vectors I got 15 degrees using the sin rule, however some people an angle of 135, which is 180-(15+30)
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cmuld
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For the tin question part C I think they asked you to find the amount of tin mined in 2023, as opposed to the part A which was up to 2020 or whatever. So you had to do the equation for n+1 (5) and subtract it with n (4). At least this is what I did? Saw it was a 2 mark and re read the question and spotted it was differently worded
Last edited by cmuld; 1 year ago
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threethreethree
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Thank god, thought i did this wrong! Fixed it.
(Original post by itskxmil)
For the cubic graph, the graph moved 2 down so there were 3 roots
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helloman1
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For the last question on vectors about a+b (mag) = a (mag) + b(mag)
I just said the length of a AND b combined was equal
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itskxmil
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For the exponentials it 15700 + 2300 which gave 18000. The other trig identity angle was 121 and the other was 301
(Original post by ak113)
1. a) find m when both lines are perpendicular, m=2
b)find x coordinate of intercepts (x=-5/2)

2. two equations to solve First was a=1/4?
second was definitely ±√2

Forgot the order so here are some of my answers:

Question on circles (centre of 2,-4) and radius of √28
the line x=k intersected at a tangent, find exact values of k, k=±√2
part c) was 2±2√7 or something like that

Queston on factorisation:
a) Prove (x-4) is a factor
b) prove the curve has two distinct roots (got x-4 as a repeated root) and -3/2 as the other root
c) Suggest the number of roots the graph f(x) - 2 had, should be three root as graph is translated by vector
(0, 2)

d)Find the value of k when f(x+k) crosses the orgin got k=4 which translated 4 to the left, or k=-3/2 which moves it 1.5 to the right

Question on trig:
a) Show that x = 2√3 when the area of the triangle is 18
b) Second question, find the length of AB, which was √84, simplifies to 2√21

Other trig question:
a) Had to show that a trig identity equals to -5cosx+4

b) solve this to get tan=-5/3. Solutions are 301 and something else i forgot

Question on quadratics with tin as a model of a quadratic
Find the value when n=1 for part a and n=4 for part c
State the max amount of tin they could mine,

Question on definitve integrals:
Had to find the x- coordinate for when x is a minimum. X=4
You then had to use this value and x=0 as your limits to differentiate the curve to get 256/3

Question on linear modelling about trees and their height and time
a) Find the relationship between H and t

H=0.31t+1.42

b) The original height was 140 cm = 1.4m, comment on the suitability of the model


Question on exponentials, initial value was like 5700+2300 = 8000
part b differential the exponent to get what they asked
part c, find the time when it is valued at £500, got 8 years 3 months

Last question on vectors:
a) state what is meant by non-zero or something to that extent
b)

|a + b| = |a| + |b|

m = |6| and |m-n|=3 and the angle between them is 30, had to find the angle between |m| and |n|

I got 15 degrees using the sin rule, however some people an angle of 135, which is 180-(15+30)
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MrRhino
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I put a and b had to be parallel
(Original post by helloman1)
For the last question on vectors about a+b (mag) = a (mag) + b(mag)
I just said the length of a AND b combined was equal
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William1247
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Rough grade boundaries?
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MrRhino
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Was it 30 degrees between vectors m and n or between m and m-n??
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itskxmil
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60% for a C
(Original post by William1247)
Rough grade boundaries?
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William1247
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How did everyone find it?
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MrRhino
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(Original post by itskxmil)
60% for a C
Last year was 47% for a C. Do you think it was that much easier tha last years paper?
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William1247
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How did u find it
(Original post by MrRhino)
Last year was 47% for a C. Do you think it was that much easier tha last years paper?
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MrRhino
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(Original post by William1247)
How did everyone find it?
I thought the exam was pretty straight forward in the end but fairly tight on time. I know a lot of people struggled with the 2 mark questions as they thought it was more complicated than just manipulating the previous answer.
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MrRhino
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(Original post by itskxmil)
Yeah I have the grade boundaries
What’s the A then?
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itskxmil
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I reckon A is like 70%. I meant the B would be 60% btw.
(Original post by MrRhino)
What’s the A then?
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Elliamy
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lol, a fire alarm went of 15 minutes into my one!
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MrRhino
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(Original post by itskxmil)
I reckon A is like 70%. I meant the B would be 60% btw.
Yeah that makes more sense. I agree. If the paper was harder than last year it will be around 65% for an A and if it was easier then around 72%
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MrRhino
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(Original post by bellell)
lol, a fire alarm went of 15 minutes into my one!
If only it had been a real fire in further maths instead and your paper burnt XD
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