Maths HL P 1 - aftermath

chaoticmess

casadenikki wrote: »

didnt get 8 c out either people get the area as 27 yeah?

I didn't get 8C either! Attempted it but ended up with a pageful of gobbledegook!

Yay I got 27 for the area too.... pretty sure that we're right on that then.
that was a lovely question, was expecting something horrible for the area bit!

Healium

mark.oc wrote: »

Q.1 (a) k = -3, t = 9

(c)(i) -3-b
(ii) -2-2b
(iii) b = -4, c = 1, d = 6

Q.2 (a) x = 3, y = -2, z = -1

(b)(i) 4
(ii) rt20 or 2rt5

Q.3 (a) x = 4, y = 2

(b)(i) ±6
(ii) -8

(c) Didn't take them down as they were all decimals.

Q.4 (a) 47/99

(b)(i) a = -42, d = 6
(ii) 0

(c)(iii) 27230

Q.5 (a) x = 2

(c)(ii) 47

Q.6 (a) x = 4/3

(b)(i) 2/5
(ii) line

(c)(i) [LATEX](-4-2xy^3)/(2+3x^2y^2)[/LATEX]
(ii) 2x + y - 6 is the tangent.

Q.7 (b)(i) 2/(1-2cosxsinx)

(c)(ii) minimum

Q.8 (a) -(cos2x)/2 + (e^4x)/4 + c

(b) 37 units

(c)(i) ln((1+sinb)/(1+sina))
(ii) ln((1+cosa)/(1+cosb))

Well... that's my fail hammered in stone

Indigo Sunrise

I thought it wasn't too bad , but now I'm disappointed that everyone thought it was easy. I was looking for an A1
2.c(ii), 8(c),3(c) and 4(c) didn't work out for me. What was 6b(ii)? Other than that it was mostly ok. I did all 8 questions and attempted every part so even if I didn't get the answer I probably picked up some marks.

casadenikki

chaoticmess wrote: »

I didn't get 8C either! Attempted it but ended up with a pageful of gobbledegook!

Yay I got 27 for the area too.... pretty sure that we're right on that then.
that was a lovely question, was expecting something horrible for the area bit!

i know i was dreading the area bit and then i nearly did a happy dance when i saw it i had so much gobbledegook i had to ask for piles of extra paper. there was no proofs at all though?? paper two shoudl have a few so!

CiaraBelle

For 6 B(ii) I said it was increasing as well. Differentiation finds the slope of the tangent to the curve so its always a line right? Or I am just waffling here...?

!?!

mark.oc wrote: »

Q.1 (a) k = -3, t = 9

(c)(i) -3-b
(ii) -2-2b
(iii) b = -4, c = 1, d = 6

Q.2 (a) x = 3, y = -2, z = -1

(b)(i) 4
(ii) rt20 or 2rt5

Q.3 (a) x = 4, y = 2

(b)(i) ±6
(ii) -8

(c) Didn't take them down as they were all decimals.

Q.4 (a) 47/99

(b)(i) a = -42, d = 6
(ii) 0

(c)(iii) 27230

Q.5 (a) x = 2

(c)(ii) 47

Q.6 (a) x = 4/3

(b)(i) 2/5
(ii) line

(c)(i) [LATEX](-4-2xy^3)/(2+3x^2y^2)[/LATEX]
(ii) 2x + y - 6 is the tangent.

Q.7 (b)(i) 2/(1-2cosxsinx)

(c)(ii) minimum

Q.8 (a) -(cos2x)/2 + (e^4x)/4 + c

(b) 37 units

(c)(i) ln((1+sinb)/(1+sina))
(ii) ln((1+cosa)/(1+cosb))

anyone get around 167 I can't remember exactly for the purple?

monaghanman10

i got 37 for the area in 8 but messed up the c part so its no good.

CantStandMeNow

mark.oc wrote: »

Think it was 37.

edit: Might as well crosspost this:

Yeah the area was definetly supposed to be 37!

johnmcdnl

complex numbers was snakey asking for polar form... that messed me up big time because i got confused as to what to od with the 2nπ when it wouldn't work out for me.. then i lost my plot and didn't know what to do..

the arg was tricky and i was only guessing that it meant argand and it took me long enough to figure that out... then i still didn't know what to do... how did you do that bit out anyways

MavisDavis

johnmcdnl wrote: »

complex numbers was snakey asking for polar form... that messed me up big time because i got confused as to what to od with the 2nπ when it wouldn't work out for me.. then i lost my plot and didn't know what to do..

the arg was tricky and i was only guessing that it meant argand and it took me long enough to figure that out... then i still didn't know what to do... how did you do that bit out anyways

That meant argand? In all honesty, I thought it was "argument". Not very clear!

Eluminous

Grand paper, S & S was easy enough to work out without knowledge of them.

None of my class knew what the hell arg was though :pac:

mark.oc

chaoticmess wrote: »

I didn't get 8C either! Attempted it but ended up with a pageful of gobbledegook!

Yay I got 27 for the area too.... pretty sure that we're right on that then.
that was a lovely question, was expecting something horrible for the area bit!

I got that at first alright, but went back and checked it. The problem was with the definite integral of the part under the x-axis at one. That was 5, taken away from -27, gives -32. Modulus of that plus the original 5 gives 37.

EuropeanSon

SantryRed wrote: »

Did people get Q8 (c) (iii) to work out? I got the answers to parts (i) and (ii) but didn't know what to do with them for the third part.

sin(pi/2 - b) =cos(b)

mark.oc

MavisDavis wrote: »

That meant argand? In all honesty, I thought it was "argument". Not very clear!

It was argument, ie. the angle between the line from the origin and the x-axis.

CantStandMeNow

CiaraBelle wrote: »

For 6 B(ii) I said it was increasing as well. Differentiation finds the slope of the tangent to the curve so its always a line right? Or I am just waffling here...?

Yeah but if the slope of the tangent is always the same then its a line.. they may give you marks for increasing if they're kind

Ashashi

I got 81 for the area, but that seems wrong. Still happy though, Q5 was amazing, the induction was grand, and the c part was fine, didn't get teh final answer though.

say I am aiming for an A2 or B1 after that, superb paper

MavisDavis

mark.oc wrote: »

It was argument, ie. the angle between the line from the origin and the x-axis.

That's what I put, even thought I couldn't get it to work out. Was it tan (y/x) or something? Like tan (8/t)?

mark.oc

CiaraBelle wrote: »

For 6 B(ii) I said it was increasing as well. Differentiation finds the slope of the tangent to the curve so its always a line right? Or I am just waffling here...?

Since the slope was constant for all values of x, it implies a line.

gant0

Not all to pleased but not mortified either as paper 1 is my weak paper.Was thrown by a few questions but hopefully well on my way to atleast a c3:D

mark.oc

MavisDavis wrote: »

That's what I put, even thought I couldn't get it to work out. Was it tan (y/x) or something? Like tan (8/t)?

Exactly.

monaghanman10

for that arguement thiingy did anyone get t =-8

EuropeanSon

MavisDavis wrote: »

That meant argand? In all honesty, I thought it was "argument". Not very clear!

It was. The argument is the angle in DeMoivres theorum. Argand is just the name of the diagrams used to illustrate complex numbers.

EuropeanSon

monaghanman10 wrote: »

for that arguement thiingy did anyone get t =-8

Yep

johnmcdnl

MavisDavis wrote: »

That meant argand? In all honesty, I thought it was "argument". Not very clear!

well according to wikipedia it's an "argument" so i got that wrong.. that question was really unfair like in fairness so...

what did the answer work out to be does anyone know

KealanOCarroll

everyone in my year got either 27 or 37 as the area....then there was me with my 127:D

1a, squared it out but didnt let each element of the quadratic equal the other side...

1c got different answers every time I tried to verify it

2b I got ab = 4 and a+b = root 20?

2c made a complete cock of it....got the jist of the proofs....perfect squares greater than zero nd that but not properly out at all

3 was a complete disaster....lucky to scrape attempt marks out of it

6 and 7....both 50 marks i reckon

8a sound, 8b proper procedure but made a knob of a substitution somewhere

8c first two bits were sound, the I = J if a+b = pi / 2, got zero equals zero but i might have made a leap of faith somewhere towards the end me thinks


Prayin for a soft Paper2

Making It Bad

mark.oc wrote: »

Think it was 37.

edit: Might as well crosspost this:

Got a lot of the same answers as you, praying for the A now. PLEASE BE NICE PAPER 2.

Ashashi

I got the right answer for 8c, but I forgot to change the limits, so I am gonna look like a sneaky bollocks trying to weave my way around the amrking scheme :P

Always disliked integration anyway.

EuropeanSon

johnmcdnl wrote: »

well according to wikipedia it's an "argument" so i got that wrong.. that question was really unfair like in fairness so...

what did the answer work out to be does anyone know

If it's the one I'm thinking of, it was t=-8.

EuropeanSon

Ashashi wrote: »

I got the right answer for 8c, but I forgot to change the limits, so I am gonna look like a sneaky bollocks trying to weave my way around the amrking scheme :P

Always disliked integration anyway.

There was no need to change limits.

Ashashi

Actually, I know what I did wrong. Substituted, but didn't fill the u back in, so I got ln a/b = ln b/a and it worked out lovely.

But shagged it up sadly. Question 5 will make up for it hopefully