****Leaving Certificate: Higher Level Maths Discussion****

deadpixel

Actually what did you guys get for the conditional probability of a true positive in the disease test? I think I had around .06 which seemed too small?

chatterboxxx95

I'm so angry about all the stats and probability and the the lack of time. That's my hope of an A down the drain
What was that trig question though seriously?? Ran out of time and just had to move on. Didn't made a huge mistake with the table so redoing it took me 10minutes. I didn't even read the question after standard deviation, just left it blank and moved on the only question I likes was the last one and other peoole didn't finish that so it's likely the last parts will be worth about 5 marks... anyway, rant over

allyb17

What was the standard deviation for voltage? I got something mad

ian5005

Could someone got through the proof of Cos2A?

chatterboxxx95

deadpixel wrote: »

Actually what did you guys get for the conditional probability of a true positive in the disease test? I think I had around .06 which seemed too small?

Same as me!! Was very confused by it as it didn't seem right

Hotale.com

allyb17 wrote: »

What was the standard deviation for voltage? I got something mad

219 I think?

Saskatchewan

A lot trickier than paper 1. Long coordinate geometry question was a surprise, the value for l was the trickiest I think. Last part of Q9 was a bit mad! Line question last part was tricky. Spent a nice bit of time on it and got out positive numbers anyway! Wasn't a nice paper in my opinion. The questions were riddled with ambiguity and errors so that will be taken into account.

Delightfully Bright

allyb17 wrote: »

What was the standard deviation for voltage? I got something mad

I got 220 volts. I'm not sure if it's right though.

Irishgirl2014

Did the theorem question with the contruction wrong can you get attempt marks or it it just an automatic 0 ?

allyb17

ian5005 wrote: »

Could someone got through the proof of Cos2A?

Cos2A = cos(A+A)
Cos (A+A) = cosAcosA - sinAsinA
=cos^2A-sin^2A

deadpixel

Hotale.com wrote: »

219 I think?

I couldn't get my calculator to work right in the exam so I guessed 212 haha, wonder if I'll get away with a slip?

Peregrine

deadpixel wrote: »

Actually what did you guys get for the conditional probability of a true positive in the disease test? I think I had around .06 which seemed too small?

I think the chance of someone having the disease was so low that you were actually more than 10 times likely to get a false positive test from someone who was well than a real positive from someone who was diseased.

MegGustaa

deadpixel wrote: »

Actually what did you guys get for the conditional probability of a true positive in the disease test? I think I had around .06 which seemed too small?

I got that too! I said that I wouldn't recommend using the test because more people who don't have the illness would test positively than people who actually did, which makes sense because if 99.7% of people (or whatever it was) don't have it, but 4% of those people will test positive anyway, a hell of a lot of people are going to test positive compared to the 0.3% of the total population who actually have it.

allyb17

Delightfully Bright wrote: »

I got 220 volts. I'm not sure if it's right though.

Phew that sounds like my answer!

aleatorio

FatRat wrote: »

OK well I have a question for you.. I did that but my answer was so tiny that I thought it was wrong so I crossed it out! It was still visible and I made a puny attempt to get an answer a different way. Will they accept the bit I crossed out?

If it's visible, id say so

deadpixel wrote: »

Actually what did you guys get for the conditional probability of a true positive in the disease test? I think I had around .06 which seemed too small?

I got 6.4% I think which seemed reasonable considering that such a large proportion were false positives :pac:

MegGustaa

Delightfully Bright wrote: »

I got 220 volts. I'm not sure if it's right though.

It would be too much of a coincidence if it wasn't 220, given that that's the standard output voltage of your AC mains, and given that it gave an approximate k value of root 2, which those of us who do Physics should recognise from root mean squared calculations

Saskatchewan

Oh and congratulations to everyone who sat the paper! May the marking schemes be forever in your favour!

Kyro

xoxuxxexaxi wrote: »

I suppose you won't , but it is a winding way and i wonder if you have enough time

It's not really, it only took a few seconds? 3/6 profit, 1/6 break even, 2/6 loss. 2/5 profit, 1/5 break even, and 2/5 loss.

Very simple and quick?

Delightfully Bright

MegGustaa wrote: »

It would be too much of a coincidence if it wasn't 220, given that that's the standard output voltage of your AC mains, and given that it gave an approximate k value of root 2, which those of us who do Physics should recognise from root mean squared calculations

Yeah I thought I recognised that number from physics alright!

ian5005

allyb17 wrote: »

Cos2A = cos(A+A)
Cos (A+A) = cosAcosA - sinAsinA
=cos^2A-sin^2A

I got that, pulled it out of the logs , hopefully 10 maybe 15 marks

robman60

ian5005 wrote: »

I got that, pulled it out of the logs , hopefully 10 maybe 15 marks

Hopefully most of the marks will be going for that because the last part was horrible.

ian5005

robman60 wrote: »

Hopefully most of the marks will be going for that because the last part was horrible.

what was the last part?

jellytots95

what did people get for the square length part for the clock :P

Peregrine

jellytots95 wrote: »

what did people get for the square length part for the clock :P

13.

Delightfully Bright

jellytots95 wrote: »

what did people get for the square length part for the clock :P

I got about 12.07 which you had to round up to 13.

Isitthough?

Nimrod 7 wrote: »

13.

is it like the diameter of the big circle plus radius of small?

Peregrine

Isitthough? wrote: »

is it like the diameter of the big circle plus radius of small?

Diameter of the big circle and small circle plus the bit between the edge of the circles and the corners will give you the diagonal.

Then you get l using Pythagoras.

MegGustaa

Delightfully Bright wrote: »

I got about 12.07 which you had to round up to 13.

I got 5 + 5(root 2) and wrote that because it *just fits* both cogs but did it say to round to the nearest whole number? Damn.

aleatorio

Nimrod 7 wrote: »

13.

I found the length of the diagonal instead because I rushed it, but had l^2 + l^2 = 17^2 written out somewhere I think.. Wonder if Ill lose many marks :P

Peregrine

aleatorio wrote: »

I found the length of the diagonal instead because I rushed it, but had l^2 + l^2 = 17^2 written out somewhere I think.. Wonder if Ill lose many marks :P

It's part of the process so you might get high or mid partial credit.