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OCR C2 exam Wed 25th May

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Reply 140
Original post by SGHD26716
x^ isn't negative, but x is. The original equation was 2logx something.


no i defo double checked it u couldnt have -3, i dont think it was 2log???
Reply 141
Original post by rewre
no i defo double checked it u couldnt have -3, i dont think it was 2log???


The first part of the question was to combine it into a single log

Then you had to solve that, but in the question it was expressed as two different logs. Putting in -3 into the calculator gives you a math error. So the only answer was 12
Original post by SGHD26716
x^ isn't negative, but x is. The original equation was 2logx something.


In the same way you'd get a math error with a power like 400, so you multiply the log by 400, you get a math error with a negative power, so you apply the log's multiplier as an indice to square it and remove the negative
Original post by SGHD26716
The first part of the question was to combine it into a single log

Then you had to solve that, but in the question it was expressed as two different logs. Putting in -3 into the calculator gives you a math error. So the only answer was 12


If you put -3 into the combined log ((-3)^2 / (-3+4)), you don't get a math error
Original post by rewre
Can someone plsss confirm , for the sum of U > sum of w , did u have to find a new first number and difference for the arithemetic because it was Un+1 it was just Un???

Also wasnt the period PIE/ A?


you could, if you wished have found the value of N with equality sign (this being critical value) and get something like 37.bla But 'is greater than' is asked for so rounding it up should give 38.
Reply 145
Original post by h3rmit
If you put -3 into the combined log ((-3)^2 / (-3+4)), you don't get a math error


im pretty sure it wasnt 2log anyway, i thought it was X-2 LOG ????????
Ive just remembered because i remember plussing 2 to the other side!
Reply 146
Original post by h3rmit
If you put -3 into the combined log ((-3)^2 / (-3+4)), you don't get a math error


What about the separated logs?
What were the equation?
Reply 147
Yes this is right since 9x^2k^2=k
Reply 148
Original post by tangotangopapa2
you could, if you wished have found the value of N with equality sign (this being critical value) and get something like 37.bla But 'is greater than' is asked for so rounding it up should give 38.


so u couldnt use the first number and D u had already found for part i ? u had to find it again with 1 , 2, 3 not using previous answer? this gave you A= 2.5 and D= 1
Reply 149
I coudnt find the 2015 c2 paper so how hard was this compared that and if so what do you guys reckon the boundaries gonna be
What was answer to question 2 on perimeter of sector my mind went blank 😞
Original post by rewre
im pretty sure it wasnt 2log anyway, i thought it was X-2 LOG ????????
Ive just remembered because i remember plussing 2 to the other side!


That's probably the other later question with 3^(x-2)

Original post by SGHD26716
What about the separated logs?What were the equation?

2log base 3 (X) - log base 3 (X+4) = 2
Edit: the combined logs and the separated logs are equal so any manipulation, including squaring to remove the negative, will produce a correct answer
(edited 7 years ago)
Original post by rewre
so u couldnt use the first number and D u had already found for part i ? u had to find it again with 1 , 2, 3 not using previous answer? this gave you A= 2.5 and D= 1


Yes you can use it but as far as I remember, U1 was 5 and Un+1 was Un+1.5 or so, giving a = 5 and d=1.5
Reply 153
Original post by tangotangopapa2
Yes you can use it but as far as I remember, U1 was 5 and Un+1 was Un+1.5 or so, giving a = 5 and d=1.5


Un = 1.5n + 3.5
Reply 154
Original post by h3rmit
That's probably the other later question with 3^(x-2)


2log base 3 (X) - log base 3 (X+4) = 2
Edit: the combined logs and the separated logs are equal so any manipulation, including squaring to remove the negative, will produce a correct answer


I got both 12 and -3, but said -3 is not valid since 2log base 3(-3) gives maths error. You could square the -3 but that's after manipulation and not the original equation. I really don't know. I wrote down 12 and -3 and then underlined 12
Reply 155
Original post by iamDev
I coudnt find the 2015 c2 paper so how hard was this compared that and if so what do you guys reckon the boundaries gonna be


I retook and would say that last years was similar in difficulty
Can you carry an error forward on core 2?
Reply 157
Original post by SGHD26716
I got both 12 and -3, but said -3 is not valid since 2log base 3(-3) gives maths error. You could square the -3 but that's after manipulation and not the original equation. I really don't know. I wrote down 12 and -3 and then underlined 12


They both worked fine for me but I'm not too sure
lol this was disgusting

Really hate AS its killing me LOOOL


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Original post by Isaacsutton123
What was answer to question 2 on perimeter of sector my mind went blank 😞


Couldn't do this one 🙂🙂🙂🙂🙂🙂🙃🙃🙃🙃🙃


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