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C2 unofficial answers

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For the second logs question, from

2^(2x+5) = 7*(2^x),

I started off by dividing both sides by 2^x, giving

2^(x+5) = 7.

I then used logs from here on out, and obtained x = -2.19. Will this still score full marks?
4cos^2x+2 = 7sin x
4 - 4sin^2x+2=7sin x
-4sin^2x+2=7sin x
4sin^2x+7sinx-2=0
y = sin^2x
4y^2+7y-2=0
(4y-1)(y+2)
so isn't y 0.25 and -2
Sin-1(0.25) = 14.5??
Reply 262
Avatar for HarrJ
HarrJ
2
Original post by UKoE Luna
The area of a sector in degrees is given by:

A=n360πr2A=\frac{n}{360}\pi r^2

So you would of gotten

A=120360πx2A=\frac{120}{360}\pi x^2

A=13πx2A=\frac{1}{3}\pi x^2

So you'd end up with the same answer either way.


Ah i see. I wasn't taught that. I was told its 1/2 r^2 θ

Which it is, but only for radians. :frown: just found this out. I did think to put it in in radians instead to be safe, but never got round to it! poo
Original post by Julieplec
Oliver, it's height*- definitely stick to maths


i am no native speaker i am sorry mr language corrector as this would be the only thing u are good at.come at me tell what i spelled wrong this time XD
Original post by Oliver123Revilo
i am no native speaker i am sorry mr language corrector as this would be the only thing u are good at.come at me tell what i spelled wrong this time XD


That's evident, your whole sentence structure is appalling to be honest
Reply 265
Avatar for boyyo
boyyo
6
Original post by AstarAstarA
Geometric:
b) 256
c) 1.602

Binomial:
A = 16
k = 7/2
B = 936

Integration:
S = 24.3

Trapezium:
a) 7
b) 20.75
c) R = 5.75

Factor theorem:
a) 5
c) (x + 2)(3x + 2)(2x - 1)

Differentiation(Q10):
a) 1/3PIx^2
d) Minimum = 120m
c) x = 16.63... => f''(x) = 0.437 > 0

Trig identities:
a) Theta = 8/15Pi , -2/15Pi
b) x = 194.5, 345.5

Circle:
a) root(34)
c) 3x + 5x - 95 = 0

Log:
i) (a - 5)/9
ii) -2.19

Likely UMS:

68 - A
57 - B
49 - C
41 - D
36 - E
U


68 for an A? Isnt that pretty high?
Original post by Saywhatyoumean


Definitely 1.602.
Original post by Julieplec
That's evident, your whole sentence structure is appalling to be honest


what is 4x4x4=?
Reply 268
Avatar for boyyo
boyyo
6
Original post by egg_fried
4cos^2x+2 = 7sin x
4 - 4sin^2x+2=7sin x
-4sin^2x+2=7sin x
4sin^2x+7sinx-2=0
y = sin^2x
4y^2+7y-2=0
(4y-1)(y+2)
so isn't y 0.25 and -2
Sin-1(0.25) = 14.5??


It was -0.25 I swear
Reply 269
Avatar for Ashy99
Ashy99
6
Posted from TSR Mobile

Were u high?
where did you see the unofficial markscheme?
Original post by Oliver123Revilo
this paper was too easy. I finished after 30 min and got bored. i want more challenging exams edexcel !!!
if u don't get 75/75 u should find the closest bridge and jump


I agree with the first bit. I finished in 15 minutes and did the paper a total of 5 times but still got 74/75

No one should be jumping off a bridge for not being as keen as us at maths
Original post by HarrJ
Ah i see. I wasn't taught that. I was told its 1/2 r^2 θ

Which it is, but only for radians. :frown: just found this out. I did think to put it in in radians instead to be safe, but never got round to it! poo


Yup happens to us all. On the last question I forgot to plug in the x value back into the equation. :3 whoops.

Original post by egg_fried
4cos^2x+2 = 7sin x4 - 4sin^2x+2=7sin x-4sin^2x+2=7sin x4sin^2x+7sinx-2=0y = sin^2x4y^2+7y-2=0(4y-1)(y+2)so isn't y 0.25 and -2Sin-1(0.25) = 14.5??


You got the question wrong it was:

4cos2x+7sinx−2=04cos^2x+7sinx-2=0

4(1−sin2x)−2=−7sinx4(1-sin^2x)-2=-7sinx

4−4sin2x−2=−7sinx4-4sin^2x-2=-7sinx

4sin2x−7sinx−2=04sin^2x-7sinx-2=0

(4sinx+1)(sinx−2)(4sinx+1)(sinx-2)

So xx is −14-\frac{1}{4}
(edited 7 years ago)
Original post by egg_fried
4cos^2x+2 = 7sin x
4 - 4sin^2x+2=7sin x
-4sin^2x+2=7sin x
4sin^2x+7sinx-2=0
y = sin^2x
4y^2+7y-2=0
(4y-1)(y+2)
so isn't y 0.25 and -2
Sin-1(0.25) = 14.5??

The function was:
4cos2(x)+7sin(x)−􀀀2=04 cos^2(x) + 7sin(x) - 􀀀 2 = 0
Original post by Oliver123Revilo
what is 4x4x4=?


64 probs
Original post by AstarAstarA
Graphically means using a graphing calculator to read off the value of the exponential.

Numerically means by finding it using trial and error (some students do this if they have no clue)


Does this apply to the sin question as well? Cause the same statement was said under the question.
Original post by don't cry-craft
Does this apply to the sin question as well? Cause the same statement was said under the question.


Yes and it's in all the recent papers. Edexcel have started doing this to avoid confusion from students disputing not getting at least marks for correct answers
Reply 277
Avatar for KJQJQJQ
KJQJQJQ
If I didn't pay attention to the range in 6b Like I got two more negative answers. How many marks will I lose? Thanks
Original post by KJQJQJQ
If I didn't pay attention to the range in 6b Like I got two more negative answers. How many marks will I lose? Thanks


You normally don't gain the second answer mark (A1) if you list other wrong solutions. I've seen this in the recent mark schemes where it specifies to not award both A1s in this case.
(edited 7 years ago)
Easy paper - last years was slightly more difficult but then again they're all standard tbh

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