Higher Maths (P1) Question 8(c)

less is more · 06-06-2008 04:58PM #1

Ok there seems to be some debate as to the correct answer, so a simple post with your answer should help clear things up. BTW it was the Integration shaded area question.

I got 19 units squared

Peslo · 06-06-2008 05:06PM

less is more wrote: »

Ok there seems to be some debate as to the correct answer, so a simple post with your answer should help clear things up. BTW it was the Integration shaded area question.

I got 19 units squared

Did anybody do what i did, and find the points of intersection, Then find the area enclosed by the curve and the line y=-5 and take away the area enclosed by the line and the line y=-5.
The intervals where from -3 to 3.

I realised at the end that there was another little bit to do, but only realised at the very end!!

NanoZoom555 · 06-06-2008 05:09PM

i got 99/8 units ^2 ,dont think its right tho,im hearing a lot of very different answers

cian1500ww · 06-06-2008 05:10PM

14

Blackangel · 06-06-2008 05:19PM

35/3 but i think its very wrong

tramoredude · 06-06-2008 05:24PM

I knew how to do it, but it looked so time consuming I just went onto Algebra, A girl in my class says she did it in "a minute or two" so she more than likely got the wrong answer too...

I bet it would take 20 minutes to do it out properly! You had to subtract the area of the rectangle + the small triangle in the 4th quadrant too, anyone spot that?

But over all it went well and I did a lot better than I thought I would

life_is_music · 06-06-2008 05:26PM

yeah i did the rectangle/triangle thingy...

Took me 4 pages to get it out

I got 79/6 i think...... or maybe 77/6

alan4cult · 06-06-2008 05:38PM

Answer is 32/3 methinks

Peslo · 06-06-2008 05:39PM

Loads of people i know spent ages doin it, a few said it took 3 or 4 pages to do too

Nanaki · 06-06-2008 05:43PM

4/3 seems vveeeerrrry wrong!
I got my limits (by plugging y=4-x^2 into the line, I think it was -1 and 3)
Integrated the curve with the limits.
Then did the line (realised halfway through - how the hell do ya intergrate y?!) and subtracted it from the curve.
Kinda noticed that part of the area is below the x axis, does that have a bearing?

Anyone want to post a worked solution?

Cokehead Mother · 06-06-2008 05:46PM

I'll LaTeX up a pretty solution - give me 5 minutes.

Rich89 · 06-06-2008 05:46PM

Me and another guy i was talking to got 32/3

Nanaki · 06-06-2008 05:53PM

Cokehead Mother wrote: »

I'll LaTeX up a pretty solution - give me 5 minutes.

excellent, thanks!

TheAmateur · 06-06-2008 05:57PM

Rich89 wrote: »

Me and another guy i was talking to got 32/3

If that means 10 and two thirds I think I got that too!

jennyq · 06-06-2008 06:05PM

Also 32/3, did it again just there to make sure.

Decerto · 06-06-2008 06:20PM

i just did it there and got 32/3 but in exam i used one wrong limit for very last bit under x axis in getting curve instead of 3 and 2 i used 3 and 1/2 anyone know what ill be docked for tht

Cokehead Mother · 06-06-2008 06:25PM

Turns out I lost the ability to LaTeX efficiently and correctly. As it transpires I have a (horrible) scanner. It's cut off at the end but the answer I have there is 32/3.

orangetictac · 06-06-2008 06:33PM

Yup thats wat i got!

hippety-pippety · 06-06-2008 06:36PM

i got 9.... any takers?
it took me a gud while bt 9 is a nice round number so i stuck with it rather than try agen.

shockingpinkdna · 06-06-2008 06:40PM

I got 8. But then again I can't do Integration!

delta214 · 06-06-2008 06:41PM

I got 32/3 also.
I just moved my x axis down so that the point where the curve and line meet is on the axis. Made it much simpler i thought

alan4cult · 06-06-2008 06:43PM

delta214 wrote: »

I got 32/3 also.
I just moved my x axis down so that the point where the curve and line meet is on the axis. Made it much simpler i thought

How do you do that method?

littlneutralone · 06-06-2008 06:45PM

If you do it right but make stupid mental calculator mistakes is it only 3 marks you lose?

Can't recall my answer. I think I did it the same way as posted above but 11.58am leaves little time for prudence.

Cokehead Mother · 06-06-2008 06:46PM

littlneutralone wrote: »

If you do it right but make stupid mental calculator mistakes is it only 3 marks you lose?

Can't recall my answer. I think I did it the same way as posted above but 11.58am leaves little time for prudence.

1 + 2 = 4 is a slip and you only lose 1 mark for them.

conor563 · 06-06-2008 06:47PM

I got 32/3. It took me ages! I got the area between the curve and the x-axis and the area between the line and the x-axis on both sides. Took the curve area from the positive area of the line and x-axis, then added that answer to the negative answer of the line and x-axis. Sorry if it sounds confusing, it very much is. Haven't a clue if its not the right answer!

irish_boy90 · 06-06-2008 06:58PM

i got 6, looked up the method in my less stress more success.
I got it wrong.

wasn't too far off it though.
didn't bother working out the real answer. P1 is over so I started on P2
only looking to pass H irish and well I did a good oral. paper 2 is geting some much needed attention this weekend

mrskinner · 06-06-2008 07:03PM

if you want to move the 2 graphs up you add 5 to each,,,,

y = 9 - x^2
and
y = 6 - 2x

integrate the curve from -1 to 3 gives 26.666
the area of the triangle is 12

the difference is 14.6666 which is the shady area?

dyle123 · 06-06-2008 07:03PM

Glad to see many other people got 32/3 because that's what I got and so did another girl in my year!

littlneutralone · 06-06-2008 07:09PM

Cokehead Mother wrote: »

1 + 2 = 4 is a slip and you only lose 1 mark for them.

Sweet. Hope they follow my method, it looked like a calculator regurgitated on the page. Actually if I'm hoping for stuff, I hope I got the answer.

Anyway. Thanks.:pac:

louise-x · 06-06-2008 07:47PM

i can't even remember what i got, but looking at all this, it was wrong

Davidius · 06-06-2008 08:27PM

That question looks big and scary to my poor 5th year brain.

Higher Maths (P1) Question 8(c)

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