FP2 Practice Exam Question

Ive got this question and its just taking me round and round in circles :s-smilie:

...

f(x)=

\frac {a+bx}{c+dx}

for some constants a,b,c,d. The curve meets the axes at the points (-1,0) and (0,1), and the line x=1 is an asymptote to the curve.

Find f(x), and state the equation of the horizontal asymptote to the curve

Help would be appreciated :biggrin:

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Reply 1

kexy

Create 2 equations from the 2 co-ords given, and then solve simultaneously? to get f(x)

As for asymptotes, remember that the bottom can never equal zero!

Reply 2

blue_n_white

ive tried all that but its really giving me nothing :frown:

Reply 3

zrancis

f(x)=\frac{a+bx}{c+dx}

when f(x)=0 the curve meets the x-axis, this happens when x=-1

so a-b=0

At f(0) the curve cuts the y-axis, this happens when y=1

so a/c=1

An assymptote at x=1 implies the denominator is 0 at this point, this happens when x=1

so c+d=0

a=c, a=b, a=-d

f(x)=\frac{a+ax}{a-ax}

f(x)=\frac{1+x}{1-x}

Reply 4

blue_n_white

cheers, thats helped a lot, +rep

Reply 5

zrancis

No problem

Reply 6

blue_n_white

have you taken fp2 yet?

Reply 7

zrancis

nope, mine's on thursday! OCR. when's yours?

Reply 8

blue_n_white

yeh same, got S1 on tues aswell. Really not prepared for any of my FP modules :s-smilie:

. What modules have you done so far?

Reply 9

zrancis

ah good old S1! I've done M1-3,S1-2,C1-4 and FP1 so far. Only FP2,3 D1 and AEA left to go lol

Reply 10

blue_n_white

AEA?? howcome your doing so many aswel? im only doing 12:

done C1-4, M1-3, FP1, D1,

just resat M3, and resitting FP1 n D1, n taking S1, FP2 n FP3 for the first time :s-smilie:

Reply 11

zrancis

Yeah I need AEA for uni. Well my college puts us through 13 modules so if theres a nasty M3/FP3 then we have D1 to fall back on. personally i slept through most of D1 so i'm hoping they dont do anthing silly this year! FP2 isnt toooo bad - especially if you look at the other syllabi

Reply 12

blue_n_white

did u take M3 a cuple of weeks ago? D1 was a b***h of a paper in january, all the past ones i was getin 90+% bt that one i got 71 :s-smilie:

what other a-levels are you taking?

Reply 13

henryt

I took the OCR MEI M3 a couple of weeks ago... It was worringly easy... But I'm worried about S3 and FP2. I'm just doing revision now!

Reply 14

zrancis

Yep. Oh I heard about that, I think our teacher gave us a warning with the past paper - maybe it'll be nicer this time :smile:

I just do business studies lol, i've got a B already and thats all my offer needs so i'm ignoring it this summer!

Reply 15

blue_n_white

wats MEI??? did the last question involve 2 pendulums?

Reply 16

zrancis

henryt

I took the OCR MEI M3 a couple of weeks ago... It was worringly easy... But I'm worried about S3 and FP2. I'm just doing revision now!

I do my best to avoid anything hardcore at this time of night, it keeps me awake!

Reply 17

zrancis

blue_n_white

wats MEI??? did the last question involve 2 pendulums?

Yeah with an oblique impact

Reply 18

blue_n_white

and underwent SHM? I didnt that was an easy paper......... thought it went well but tough :s-smilie:

Reply 19

henryt

blue_n_white

wats MEI??? did the last question involve 2 pendulums?

MEI is OCR's sister syllabus in Maths. Maths in Education and Industry, or something equally stupid. My last question involved dragging a solid of revolution using a rope across a plane and finding the minimum value for the coefficient of friction.