Math Paper 12 May/June 2013

[razahayat777]

i got 60 and 40 :/

thats right

 

[rose1700]

60 & 40

 

[Anastasia Shev]

any threshold predictions?

 

[dana xP]

wht was the answer for question 7 ??
and what was K in the sequence question ??
oh and about the cuve question was the function "increasing , decreasing or neither ? "

 

[110abedi]

Can anyone post the question number 7 of reflection.. asap

 

[Kangxidi]

The question gives point R (-1.3) and line of 3y + 2x = 33 as the mirror. We are looking for the image of R, (let's name it as P)

Rearranging the equation of the mirror gives us y = -2x/3 + 11

Therefore gradient (m) of mirror is -2/3.

Since we understand that the line PR will be PERPENDICULAR to mirror (properties of reflection), therefore m of PR = 1.5.

Work out the equation of PR from the point (-1,3) and m of 1.5

y - 3 = 1.5 (x+1)

y = 1.5 x + 4.5

Another properties of mirror is that distance from object to mirror = distance from image to mirror. Therefore point of intersection of line PR and the mirror will be the MIDPOINT for line PR.

Working out simultaneous equation on PR and mirror,

y = 1.5 x + 4.5
y = -2x/3 + 11

1.5 x + 4.5 = -2x/3 + 11

9x + 27 = -4x + 66

13x = 39
x = 3

Subs x = 3 to any of the 2 equation above, we will get y = 9

Since we know R, and the midpoint, we can work out P.

(-1 + x)/2 = 3 for the x-coordinate and (3+y)/2 = 9 for the y-coordinate

Therefore x = 7 and y = 15

So point P = (7.15)

 

[Kangxidi]

wht was the answer for question 7 ??
and what was K in the sequence question ??
oh and about the cuve question was the function "increasing , decreasing or neither ? "

dy/dx has a value of < 0 for all values of x (and that includes the domain that they give)

So it's a decreasing function.

 

[FRENZYAMU]

dy/dx has a value of < 0 for all values of x (and that includes the domain that they give)

So it's a decreasing function.

dy/dx didnt ever go negative since there ws a square in the denominator although it did decreased for increasing x so i wrote decreasing,,,,btw ppl have bee saying that domain of f inverse ws not only with -2.5 but the limit had a zero too ! :S

 

[FRENZYAMU]

Guys, I have a really important question that is bothering me, if anyone has some experience with the topic - any help would be VERY appreciated. Please help me!
So I, being very silly, managed to run out of paper (even though we were given 16 sheets to answer on lol), because I answered one question on each sheet, and then moved on to a new sheet if I finished the question even though half of the sheet might have been blank. Anyway, when I reached the latter, longer questions such as question #7, which needed a lot of working, I started to answer it on like page #15 of the answer booklet, and then ran out of space, so I had to go back to like page #3 where I wrote: Question 7 (cont'd) and then continued answering the question, while the first half of that paper is dedicated to like question 2.
I know examiners mark these papers in order they are given, so when an examiner marks my papers, he'll come across paper #7 (cont'd) first! Will he then ignore it until he gets to the first part of question 7 and then come back to the cont'd part, or will he not give me any marks for it? Gosh I am so worried about it, if anybody knows anything about how these papers are marked and if the examiner will accept my form of answering, please help me!! I'm worried sick over here!

thats y they give EXTRA sheets !

 

[iKhaled]

Guys, I have a really important question that is bothering me, if anyone has some experience with the topic - any help would be VERY appreciated. Please help me!
So I, being very silly, managed to run out of paper (even though we were given 16 sheets to answer on lol), because I answered one question on each sheet, and then moved on to a new sheet if I finished the question even though half of the sheet might have been blank. Anyway, when I reached the latter, longer questions such as question #7, which needed a lot of working, I started to answer it on like page #15 of the answer booklet, and then ran out of space, so I had to go back to like page #3 where I wrote: Question 7 (cont'd) and then continued answering the question, while the first half of that paper is dedicated to like question 2.
I know examiners mark these papers in order they are given, so when an examiner marks my papers, he'll come across paper #7 (cont'd) first! Will he then ignore it until he gets to the first part of question 7 and then come back to the cont'd part, or will he not give me any marks for it? Gosh I am so worried about it, if anybody knows anything about how these papers are marked and if the examiner will accept my form of answering, please help me!! I'm worried sick over here!

don't worry man the examiner will look at every thing written on the paper and ur paper is not just seen by one examiner. i heard it is rechecked by the chief examiner so if the chief examiner noticed that the junior examiner who marked ur paper didn't check the continued part or whatsoever then he can lose his job so don't worry every thing is checked if u wrote on the answer booklet.

 

[mastermindh]

ye

dy/dx didnt ever go negative since there ws a square in the denominator although it did decreased for increasing x so i wrote decreasing,,,,btw ppl have bee saying that domain of f inverse ws not only with -2.5 but the limit had a zero too ! :S

yeah
it was less than zero too

 

[Kangxidi]

dy/dx didnt ever go negative since there ws a square in the denominator although it did decreased for increasing x so i wrote decreasing,,,,btw ppl have bee saying that domain of f inverse ws not only with -2.5 but the limit had a zero too ! :S

I think the dy/dx has a negative sign somewhere on it to make it < 0, I myself am not exactly sure what I wrote, but as far as I could remember that is what I did. Correct me if I'm wrong, though.

 

[ali khan saaed]

whts the answer for 10 b

 

[Kangxidi]

whts the answer for 10 b

7/6.

 

[s_hithappens]

i also had problem with the geometric progression one!! i didnt have enough time to figure it out, how did you do it guys? did you have 3 equations??

also i actually found the reflection question not so hard, though i must admit it wasnt so straightforward as most p1 questions are- and there were a LOT of steps!!

also i couldnt do the unit vector question. I DONT KNOW HOW TO DO UNIT VECTORS and im taking as and a2 together this time. Allah help me.

btw for the last integration question, did you guys get an area something like 2.9 or something??

 

[ali khan saaed]

7/6.

10b not 11b

 

[Kangxidi]

10b not 11b

Right thank you for pointing it out. I can't remember what was 10B, but if we are talking about the K values, it would be -21 AND 63.

 

[Kangxidi]

i also had problem with the geometric progression one!! i didnt have enough time to figure it out, how did you do it guys? did you have 3 equations??

also i actually found the reflection question not so hard, though i must admit it wasnt so straightforward as most p1 questions are- and there were a LOT of steps!!

also i couldnt do the unit vector question. I DONT KNOW HOW TO DO UNIT VECTORS and im taking as and a2 together this time. Allah help me.

btw for the last integration question, did you guys get an area something like 2.9 or something??

Last integration question: 7/6.

 

[ali khan saaed]

THERE WAS 2 K THINGS 1 FOR VECTORS ONE FOR SEQUENCES

 

[Kangxidi]

I really couldn't remember the vector one, sorry to say, but if you are talking about the sequences that one should be it.