Edexcel Core 3 - 21st June 2016 AM

I found that really hard but the consensus was that it wasn't impossible but a 7/10 for difficulty.

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Reply 1321

d14m

2

can anyone remember the range and number of solutions for the tan4x question?

Reply 1322

Yua

14

Original post by Michaelj99

8b) 6cot2x+3tanx=Cosec^2x-1 -------------> 3Cotx=1+cot^2x-2------> Cot^2x-3Cotx-1=0 and then quadratic formula. anyone remember the range? i only got 3 solutions i believe

was 4 solutions

Reply 1323

Aprkrheiqkk

1

Original post by blahblah21

Q1a, x=6, x=-5
b. a=6
2a. dy/dx = (20-4x^2)/(x^2+5)^2
b. x>rt(5) x<-rt(5)
3a. rt(5)cos(theta +26.57)
b. theta = 33.0, 273.9
c. theta = 86.1
4a. y=21, x=ln(2.5)
y=25 (k=25)
b. Proof
c. x1= 1.4368
x2= 1.4373
d. Show the change in sign. (gradient function)
5i. Turning points: 0.9463
ii. 0.5cosec(4y)
6a. A=3 B=4
b. x+2y-35=0 (or equivalent)
7a. arcsin(x) graph
b. x= -(2+rt(3))/2
8a. Proof
b. x= 0.294, -1.277, 1.865 and 1 more I think
9a. 6.740
b. Proof
c. T = 5ln(2+(2/e))

Do you remember the range of x for q. 5(i)??

Reply 1324

squirble

3

What was the first part of the first question as i think i might have misread it ?

Reply 1325

NadiCall

Can anyone remember the marks for each question part???

Reply 1326

nadz_98

4

For 7b if I left my answer as sin(-pi/3) -1 which is the same answer as your value for x would I still get full marks?

Reply 1327

Yua

14

Original post by KellyLouise0

anyone remember the number of marks for the proof of root in the interval question? (last part of Q4, i think)
I ****ed up, couldn't find a sign change :frown:

any marks for just stating the interval to be used at all?

don't think so

Reply 1328

iofeeoijse

1

Original post by d14m

can anyone remember the range and number of solutions for the tan4x question?

i think it was between pi/2 and pi/4

Reply 1329

Yua

14

Original post by nadz_98

For 7b if I left my answer as sin(-pi/3) -1 which is the same answer as your value for x would I still get full marks?

doubt it

Reply 1330

ColeNate

7

Anyone know what Question 3 asked?
(the one with k, a and y). 4e^2x-24 or something

Reply 1331

Adz_94

Other then 7b i got the same as u! So i hope ur right looool

Original post by blahblah21

Q1a, x=6, x=-5
b. a=6
2a. dy/dx = (20-4x^2)/(x^2+5)^2
b. x>rt(5) x<-rt(5)
3a. rt(5)cos(theta +26.57)
b. theta = 33.0, 273.9
c. theta = 86.1
4a. y=21, x=ln(2.5)
y=25 (k=25)
b. Proof
c. x1= 1.4368
x2= 1.4373
d. Show the change in sign. (gradient function)
5i. Turning points: 0.9463
ii. 0.5cosec(4y)
6a. A=3 B=4
b. x+2y-35=0 (or equivalent)
7a. arcsin(x) graph
b. x= -(2+rt(3))/2
8a. Proof
b. x= 0.294, -1.277, 1.865 and 1 more I think
9a. 6.740
b. Proof
c. T = 5ln(2+(2/e))

Reply 1332

QueenOfNachos

6

I left out #3c ****ing hell. How many marks were there in #3c?

Reply 1333

Michaelj99

7

Original post by Yua

was 4 solutions

ah oops

Reply 1334

Hazel37

5

Original post by KellyLouise0

anyone remember the number of marks for the proof of root in the interval question? (last part of Q4, i think)
I ****ed up, couldn't find a sign change :frown:

any marks for just stating the interval to be used at all?

I couldnt get a change of sign but you get a mark for using the upper and lower bounds .
My friend did it and you had to take away 2x + 43 away from the gx at the beginning of the equation, then sub the values into that.

Reply 1335

Whizbox

7

Original post by Aprkrheiqkk

Do you remember the range of x for q. 5(i)??

-pi to +pi

Reply 1336

BSLMaths

1

Original post by thehollowcrown

i got 0.1609 for the turning point question, other people have been saying different, so now i'm like shizzz was my calculator in the wrong setting

The turning point had to be between pi/4 and pi/2 so the answer was 0.9 something :/

Reply 1337

Amyfrancis97

1

Original post by blahblah21

Not too sure its one of the 2, because I remember seeing 32 and 3, so I think 1 of us just read the signs wrong, worst case one of us will lose 2 marks