AS math 9709/May June/2018/ Paper 12 Hard Or Easy?

[dwightedknight]

Hi all,
I took the AS Math (9709/12) exam last week.

My answers were as follows; (I got most of the things right (they matched with others), ill include the correct answers of the few Q's I got wrong, also can someone grade my paper? ty ). The exam was mostly straightforward, I'd say a bit more difficult than m/j 2017 though, Expect the threshold to be at around 58 - 62.

Binomial Expansion
(i) a=3

Quadratics
(i) k>9
(ii) k = 11 (tangent)

Series
a = 8000; r = 1.02
(i) T12= 9950 (or EQ) [I too, took n as 13 [(cuz it said, the 12th week after the first week, so I did 12+1, oh well) but my ratio was correct, so I guess I'll get 1 mark for that]
(ii) S12 = 107000 [I took n as 12 in part ii lolz, but I wrote my answer as 107300, would a mark be deducted?]

Trig Function (cosine)
f (x) = - a + bcosx
(i) a = 7, b = - 4
(ii) k>3 AND k<11 [I messed this one up, i wrote k =3 and did a little bit of working, would I be given any credit?]

Vectors
(i) People have already posted the answers for the vectors CA & DA, also I don't remember them
(ii) Angle CAD = 34.7 (this is the correct answer)

Circular Measure
(i) It was a "show that" question, I'm assuming most of you got it right (so did I)
(ii) Area = 87.8

Coordinate Geometry
(i) h = 2 & k = 36 [MP was (14,10) not (12,10)]

Differentiation/Integration
(i) dy/dx = √4x + 1 ; where c = 1/2 (Equation of line)
(ii) dx/dt = 0.02

Functions
(i) 25 - 2(x+3)^2 [Completing the square]
(ii) Stationary Point (-3, 25)
(iii) k = -3
(iv) g^-1(x) = -3 +-√25-x/2

Trigonometry
(i) - 2sinx + 3cosx =0
= -33.7, Solutions = 146.3, 326.3
(ii) Sketching was pretty straightforward
(iii) The answer to this question was already there in the first part x< 146.3 AND x<326.3 [I, unfortunately, got this one wrong, I wrote x>90 and x>146.3, 326.3? lol ik zero there]

Integration
(i) y = x was easily proved, (3=3)
(ii) Volume = 32/3 pi

Good luck for S1/M1 folks!

My answer to binomial expansion, integration, trigonometry and differentiation matches. I don't remember about the rest. For the functions, I believe the answer was -3 +√(25-x/2) not +-.

 

[Tauqir_hamed]

My answer to binomial expansion, integration, trigonometry and differentiation matches. I don't remember about the rest. For the functions, I believe the answer was -3 +√(25-x/2) not +-.

The square root of the term is +- . but we need to consider only the + one. am I right ? Also, I don't remember a stationary point finding question below the 25 - 2 ( x + a ) ^2 part

 

[Asher*]

My answer to binomial expansion, integration, trigonometry and differentiation matches. I don't remember about the rest. For the functions, I believe the answer was -3 +√(25-x/2) not +-.

that's a typing error on my part sorry ill edit it

 

[Tauqir_hamed]

was there a stationary point finding question ?? i dont remember seeing such a thing.
and talking about may june 2017, the paper was super easy and still the threshold was 63. no way this is gonna be above 60.. most have spoiled it..

that's a typing error on my part sorry ill edit it

 

[Asher*]

was there a stationary point finding question ?? i dont remember seeing such a thing

yeah; there was, the x coordinate of the SP was the answer to the next part where you had to find k.

 

[Tauqir_hamed]

yeah; there was, the x coordinate of the SP was the answer to the next part where you had to find k.

I know that.. but did it specifically ask to write down the stationary point as well?

 

[Asher*]

I know that.. but did it specifically ask to write down the stationary point as well?

yes it did

 

[Paula V]

If you see many past papers, you'll find that marks will be most likely be awarded for all n = 11, 12, 13. Stop worrying.

yeah, plus there are method marks too

 

[Paula V]

Hi all,
I took the AS Math (9709/12) exam last week.

My answers were as follows; (I got most of the things right (they matched with others), ill include the correct answers of the few Q's I got wrong, also can someone grade my paper? ty ). The exam was mostly straightforward, I'd say a bit more difficult than m/j 2017 though, Expect the threshold to be at around 58 - 62.

Binomial Expansion
(i) a=3

Quadratics
(i) k>9
(ii) k = 11 (tangent)

Series
a = 8000; r = 1.02
(i) T12= 9950 (or EQ) [I too, took n as 13 [(cuz it said, the 12th week after the first week, so I did 12+1, oh well) but my ratio was correct, so I guess I'll get 1 mark for that]
(ii) S12 = 107000 [I took n as 12 in part ii lolz, but I wrote my answer as 107300, would a mark be deducted?]

Trig Function (cosine)
f (x) = - a + bcosx
(i) a = 7, b = - 4
(ii) k>3 AND k<11 [I messed this one up, i wrote k =3 and did a little bit of working, would I be given any credit?]

Vectors
(i) People have already posted the answers for the vectors CA & DA, also I don't remember them
(ii) Angle CAD = 34.7 (this is the correct answer)

Circular Measure
(i) It was a "show that" question, I'm assuming most of you got it right (so did I)
(ii) Area = 87.8

Coordinate Geometry
(i) h = 2 & k = 36 [MP was (14,10) not (12,10)]

Differentiation/Integration
(i) dy/dx = √4x + 1 ; where c = 1/2 (Equation of line)
(ii) dx/dt = 0.02

Functions
(i) 25 - 2(x+3)^2 [Completing the square]
(ii) Stationary Point (-3, 25)
(iii) k = -3
(iv) g^-1(x) = (25-x/2)^-1/2 -3

Trigonometry
(i) - 2sinx + 3cosx =0
= -33.7, Solutions = 146.3, 326.3
(ii) Sketching was pretty straightforward
(iii) The answer to this question was already there in the first part x< 146.3 AND x<326.3 [I, unfortunately, got this one wrong, I wrote x>90 and x>146.3, 326.3? lol ik zero there]

Integration
(i) y = x was easily proved, (3=3)
(ii) Volume = 32/3 pi

Good luck for S1/M1 folks!

I completely forgot there was a stationary points question. I hope i got it right, the numbers seem very familiar.

 

[Asher*]

Can anyone please try and grade my paper? If there isn't any leniency in checking, how many marks would I lose?//How many marks would I need in S1, in order to score an A?

 

[Paula V]

Can anyone please try and grade my paper? If there isn't any leniency in checking, how many marks would I lose?//How many marks would I need in S1, in order to score an A?

I got most of the same answers except the one with the sequences (I took n as 12, I’m sure it’s 12, but you’d still get method marks), the one under the sketch and the circular measure one (I wanted to go with a way more complicated method than it was so that’s why I couldn’t prove it and I did a really stupid mistake in ii) which is why I got a wrong answer). I’m sure even with these mistakes you’d still get an A and it depends on the threshold and how lenient the ms is but I’d say it’s at least a mid-A so don’t worry

 

[Paula V]

was there a stationary point finding question ?? i dont remember seeing such a thing.
and talking about may june 2017, the paper was super easy and still the threshold was 63. no way this is gonna be above 60.. most have spoiled it..

Yeah, I agree, I don’t think it will be above 60 either. Plus, again, it was easy to make stupid mistakes at a lot of the questions so...

 

[Tauqir_hamed]

I completely forgot there was a stationary points question. I hope i got it right, the numbers seem very familiar.

Was the stationary point question a different question ?? Or was it under the same question that said to express in the form a ( x + b ) ^ 2....

 

[Paula V]

Was the stationary point question a different question ?? Or was it under the same question that said to express in the form a ( x + b ) ^ 2....

It could have been, because I don’t really remember there being 4 subpoints but I do remember derivating the function and getting -3. It could have also been in the same question as the k=-3.

 

[Paula V]

Was the stationary point question a different question ?? Or was it under the same question that said to express in the form a ( x + b ) ^ 2....

Ooooooh, wait, I remember it now. Yeah, it was a different question, but I’m pretty sure it was a one point question.

 

[Tauqir_hamed]

there were only 3 questions on that part bro
i ) find in the form a ( x + b ) ^ 2 ..
ii ) least value for no inverse or sth like that
iii ) the inverse of the function

I dont remember anything asking for stationary point

Ooooooh, wait, I remember it now. Yeah, it was a different question, but I’m pretty sure it was a one point question.

 

[Paula V]

there were only 3 questions on that part bro
i ) find in the form a ( x + b ) ^ 2 ..
ii ) least value for no inverse or sth like that
iii ) the inverse of the function

I dont remember anything asking for stationary point

I think it was either a really small question with a few lines under i) or it was in the same question with the value of k for which the curve has an inverse. But I’m sure there was a stationary point question.

 

[Tauqir_hamed]

I think it was either a really small question with a few lines under i) or it was in the same question with the value of k for which the curve has an inverse. But I’m sure there was a stationary point question.

ohh i see...
could you tell me what method mark actually means..
in the question where we had to prove that the line y= x intersects the tangent ( or something similar ) . I found out the points to be ( 2, 4 ) ( 6, 4 ) .. then , i made a silly mistake in differentiating y.. and thus, while i did calculate the slope and equations of the tangents , they won't be correct since i got the differentiating part wrong. How many marks do you think will I be awarded out of 6 ?

 

[Paula V]

ohh i see...
could you tell me what method mark actually means..
in the question where we had to prove that the line y= x intersects the tangent ( or something similar ) . I found out the points to be ( 2, 4 ) ( 6, 4 ) .. then , i made a silly mistake in differentiating y.. and thus, while i did calculate the slope and equations of the tangents , they won't be correct since i got the differentiating part wrong. How many marks do you think will I be awarded out of 6 ?

It means that even if the answer is wrong you can still get marks for using a correct method (because they can see you know how to solve it). In your case, (it depends a lot on how lenient the marking scheme is) I’d say maybe 4/6? Did you get to a conclusion where the y is equal to x?

 

[DudeWithoutName]

the question where they asked us to find k such that 7-4cos(x)=k has no solutions... will i get the mark if, instead of drawing a graph, i rearrange it to cos(x)=(7-k)/4 and then solve the two inequalities (7-k)/4<-1 and (7-k)/4>1 to obtain the correct answers?