[Sagacious]

There were 4 values, anybody who says otherwise has got it wrong; most likely, the whole question, because I don't see how one can obtain 3 correct ones and then ignore the last one?

1/sin^2(2x+0.6) = 16
sin^2(2x+0.6) = 1/16
sin(2x+0.6) = +/- 1/4

then, if you type sin (2x+0.6) into a graphical calculator and then type in 0.25, or -0.25, you receive the 4 intercepts that satisfy the equation.

[Sykikdoc1993]

I am soo annoyed with myself . i made so many silly mistakes . i substracted 0.6 instead of adding it and in the substitituion question i differentiated x^4 to 3x^3 and got 1/3 ln(3/2) -1/9 . Do the examiners allow ecf ? how many marks would i have lost in these 2 questions ?

[stevop21]

(Original post by Sykikdoc1993)
I am soo annoyed with myself . i made so many silly mistakes . i substracted 0.6 instead of adding it and in the substitituion question i differentiated x^4 to 3x^3 and got 1/3 ln(3/2) -1/9 . Do the examiners allow ecf ? how many marks would i have lost in these 2 questions ?

I've seen on some past papers that if you integrate incorrectly but put in the limits and get the correct answer from your integral, then you will get some marks

[kenau]

(Original post by darkshadow1111)
For god sakes there were 4 values. Do it right now if you want. sin^-1(-1/4)=-.253
pi--.253=3.294

sin^-1(1/4)=.253
pi-.253=2.889

therefore 2x-0.9=-0.253,3.294,0.253,2.889
work that out and you get 4 values.

you got the wrong figure,that should be 2x-0.6
cosec^2(θ)=16
cosec(θ)=4,-4
∴sinθ=1/4 or sinθ=-1/4
θ=0.25,2.89,3.39,6.03
∵θ=2x-0.6
∴2x-0.6=0.25,2.89,3.39,6.03
x=0.43,1.75,2.00,3.32(2 d.p.)<- - out of range
AS the domain is 0<x≦pi
remember pi=3.14

[kenau]

(Original post by Sagacious)
There were 4 values, anybody who says otherwise has got it wrong; most likely, the whole question, because I don't see how one can obtain 3 correct ones and then ignore the last one?

1/sin^2(2x+0.6) = 16
sin^2(2x+0.6) = 1/16
sin(2x+0.6) = +/- 1/4

then, if you type sin (2x+0.6) into a graphical calculator and then type in 0.25, or -0.25, you receive the 4 intercepts that satisfy the equation.

you got the wrong figure as well,it should be 2x-0.6

[mojopin1]

The answer to the trig question is 0.17, 0.43, 1.74, 2.00, I just worked it out again. The most likely one people have missed is (2x-0.6) = -0.252, (x) = 0.17.

[Sagacious]

(Original post by kenau)
you got the wrong figure as well,it should be 2x-0.6

That makes sense! I was worrying that I did it wrong because I re-did it on my graphical calculator after the exam and I wasn't recognising the numbers... but now you have mentioned that, I have re-done it and I recognise all the numbers, which are within the quote below.

*There are still 4 values, like he has mentioned below.

(Original post by mojopin1)
The answer to the trig question is 0.17, 0.43, 1.74, 2.00, I just worked it out again. The most likely one people have missed is (2x-0.6) = -0.252, (x) = 0.17.

[henchness]

If anyone remembers any questions can you please post them up

[raveen789]

really annoyed made so many silly mistakes, the whole paper was fine up to Q8/Q9 really annoyed that months of hard work might have ruined by chances of an A grade because of two questions, now im under pressure for C4 (this was my first sitting of C3 btw)

Do you guys think that the boundaries will be similar to June 2011? :/

[darkshadow1111]

(Original post by raveen789)
really annoyed made so many silly mistakes, the whole paper was fine up to Q8/Q9 really annoyed that months of hard work might have ruined by chances of an A grade because of two questions, now im under pressure for C4 (this was my first sitting of C3 btw)

Do you guys think that the boundaries will be similar to June 2011? :/

I think they will be kinda high tbh. A lot of people found that paper easy. Im kinda in the same sistuation as you needed a high grade in this to increase my chances of getting an A star but i think im going to get a low a due to silly mistakes. Its like i couldnt even see properly, the question said the mass was 8 my mind somehow converted this to 12. I can only afford to lose 1 or 2 marks in c4

[mojopin1]

I got 73 in january without answering some questions, so i'm quietly confident i've improved my score even though i've made quite a few errors in this. I resat C1 and did M1 for the first time so hopefully i'll have 10-15 ums to play with. I'm trying my absolute hardest for C4 though.

[127arin]

(Original post by raveen789)
really annoyed made so many silly mistakes, the whole paper was fine up to Q8/Q9 really annoyed that months of hard work might have ruined by chances of an A grade because of two questions, now im under pressure for C4 (this was my first sitting of C3 btw)

Do you guys think that the boundaries will be similar to June 2011? :/

I think the grade boundaries will be standard like 60-62 for an A it was a fair paper not hard nor easey

[raveen789]

(Original post by 127arin)
I think the grade boundaries will be standard like 60-62 for an A it was a fair paper not hard nor easey

id be happy with that well the 60 bit haha, June 2011 was 59 for an A which is why i was asking if you guys thought it was similar in difficulty. I need to get 159 UMS out of the 2 modules to to get an A. But i also resat core 2 and i got 68 UMS last year :P hopefully fingers crossed ive gained some marks extra of it! But other than that all i can do is hope i can do well in Core 4. I am finding C4 much hardr than C3 though :/

[127arin]

(Original post by raveen789)
id be happy with that well the 60 bit haha, June 2011 was 59 for an A which is why i was asking if you guys thought it was similar in difficulty. I need to get 159 UMS out of the 2 modules to to get an A. But i also resat core 2 and i got 68 UMS last year :P hopefully fingers crossed ive gained some marks extra of it! But other than that all i can do is hope i can do well in Core 4. I am finding C4 much hardr than C3 though :/

Ah dont worry im sure ull get it and plus since ur in A2 core 2 must have gone gud for u coz i also resat it and it really helps when ur in A2 and to be honest i dint find june 11 so hard but a bit harder than this paper which is why i think the grade boundaries will be average like 60-62 . i think we shud just work toward gettin a gud grade for core 4 which is harder but just put the work in and ull be fine!

[raveen789]

(Original post by 127arin)
Ah dont worry im sure ull get it and plus since ur in A2 core 2 must have gone gud for u coz i also resat it and it really helps when ur in A2 and to be honest i dint find june 11 so hard but a bit harder than this paper which is why i think the grade boundaries will be average like 60-62 . i think we shud just work toward gettin a gud grade for core 4 which is harder but just put the work in and ull be fine!

Yeah I am finding core 4 quite hard, i thought Core 2 was quite a hard paper tbh core 3 did help me out in a lot of it, but there were thing i could not do! but the way i see it is i got 68 last year i hope ive improved on that, ive got more to gain I felt sorry for people in year 12 though. I thought June 11 core 3 paper was similar to this one, if grade boundaries are slightly higher they should not be (fingers crossed) too much higher

[127arin]

(Original post by raveen789)
Yeah I am finding core 4 quite hard, i thought Core 2 was quite a hard paper tbh core 3 did help me out in a lot of it, but there were thing i could not do! but the way i see it is i got 68 last year i hope ive improved on that, ive got more to gain I felt sorry for people in year 12 though. I thought June 11 core 3 paper was similar to this one, if grade boundaries are slightly higher they should not be (fingers crossed) too much higher

yh core 2 was a beast and same here those year 12s dint see it comin, but yh hopefully grade boundaries are similar! so wat r u expectin the boundaries for core 3 to be like?

[raveen789]

(Original post by 127arin)
yh core 2 was a beast and same here those year 12s dint see it comin, but yh hopefully grade boundaries are similar! so wat r u expectin the boundaries for core 3 to be like?

range of 59-62 ish for an A no idea for A*, they seem similar each year even the hardest paper Jan 12 was still 57 for an A nothing below and June 11 and Jan 11 both 59 for an A. People may have not found it a really hard paper but if people have made silly mistakes then in theory it should effect the boundaries.

What about you?

[127arin]

(Original post by raveen789)
range of 59-62 ish for an A no idea for A*, they seem similar each year even the hardest paper Jan 12 was still 57 for an A nothing below and June 11 and Jan 11 both 59 for an A. People may have not found it a really hard paper but if people have made silly mistakes then in theory it should effect the boundaries.

What about you?

yup same here i think 59-62 max would be an A grade boundary i reckon an A* would be 67 or 68ish coz i really dont see why they would put the grade boundaries higher i knw ive made some silly mistakes and other ppl would have too!

[kitkat19]

Easy but made silly mistakes -.-

[raveen789]

(Original post by kitkat19)
Easy but made silly mistakes -.-

This thread is pretty old xD

I like Core 3 in that it helped me get an A overall, I hate Core 3 because it stopped me from getting an A* I managed to do a lot better in Core 4