***2015 LC Maths Paper 1 - Higher Level - June 5th***

aaronlalorf

Anyone else scared of the Maths boys at the top throwing HL an awful enough paper 2 after this controversy?

Kremin

MmmPancakes wrote: »

my bad, feeling a bit bitter/skeptical towards people in the OL thread saying we had it easy and that they would have passed higher but failed ordinary.

Just understand people's emotions are running a bit high right now, a lot of them think they just failed and have to repeat the year.. understandably they're angry.

student625

Magnate wrote: »

Goddamnit...

That's it I think I shall bid farewell to this thread, that was probably the question I was most confident about.

Are you sure it wasn't 8?

ya! I got 8 too! also, for longest day of year in Q9, anyone else go with June 21st and work from there? the question did say solve "hence OR otherwise"???

Kremin

aaronlalorf wrote: »

Anyone else scared of the Maths boys at the top throwing HL an awful enough paper 2 after this controversy?

Well, the paper is already made... I don't see why they'd change higher level at this stage, they MAY use a different OL paper to ease some peoples anger though? But hey.. some peoples difficult could be anothers easy... someones going to be angry inevitably


Honestly they will probably just adjust marking scheme according to performance of students, again.. they will not fail everybody.

MmmPancakes

Kremin wrote: »

Just understand people's emotions are running a bit high right now, a lot of them think they just failed and have to repeat the year.. understandably they're angry.

They're going to be delighted with how front-loaded their marking scheme will be, so

wooitslucy

Anyone remember what ye did for the first two parts of the financial maths question?

Kremin

wooitslucy wrote: »

Anyone remember what ye did for the first two parts of the financial maths question?

1+i=(1+i)^12... just use the appropriate one to convert to apr or monthly rates...

also note, the i's are actually different values... I usually dont write two and initially put the percentage they give you.

MmmPancakes

wooitslucy wrote: »

Anyone remember what ye did for the first two parts of the financial maths question?

http://prntscr.com/7dm0cl this was the first part iirc, the answer is like 4.something%. Second part is the same except you have to solve for the other i

Kremin

Also the financial maths question may have been easy if you knew hwat you were doing but I'm willing to bet quite a lot of people 1.) forgot to convert the 10 years to months when using a monthly rate. 2.) Used the wrong type of interest 3.) Calculated the annual repayment and not the monthly 4.) Used 119 months instead of 120...

theyre only minor errors of course...

Maybe they should have asked to verify with a geometric series to show a wide understanding of the course.

student625

Kremin wrote: »

Also the financial maths question may have been easy if you knew hwat you were doing but I'm willing to bet quite a lot of people 1.) forgot to convert the 10 years to months when using a monthly rate. 2.) Used the wrong type of interest 3.) Calculated the annual repayment and not the monthly 4.) Used 119 months instead of 120...

theyre only minor errors of course...

Maybe they should have asked to verify with a geometric series to show a wide understanding of the course.

I wasn't sure if to use 119 or 120 months so I did out both solutions. will I still get full marks for the right answer even though I chanced my arm and gave two solutions?

Peregrine

MmmPancakes wrote: »

my bad, feeling a bit bitter/skeptical towards people in the OL thread saying we had it easy and that they would have passed higher but failed ordinary.

As Kremin said, emotions are running high and they're understandably upset. I had a look at the paper and it was completely different to what they were used to. I have no doubt that if it was the HL paper that was different and difficult, most of this thread would be up in arms about it! :P

Magnate

student625 wrote: »

ya! I got 8 too! also, for longest day of year in Q9, anyone else go with June 21st and work from there? the question did say solve "hence OR otherwise"???

Nah it was definitely 14, we didn't include the balls bouncing up as well as down. There was a good explanation a page or two after that. We should still get a good few attempt marks anyway.

As for the longest day of the year, yep I went straight for the summer solstice then subbed in the day before it and the day after to verify that it was the longest.

Kremin

student625 wrote: »

I wasn't sure if to use 119 or 120 months so I did out both solutions. will I still get full marks for the right answer even though I chanced my arm and gave two solutions?

I think you actually might? Someone posted yesterday saying never tippex work as often, students who put lines through incorrect work actually get more marks for that work than their "correct" solution

dazzadazza

Will I get any attempt marks for the longest day if I attempted to differentiate the function and let it equal to 0, to find maximum day length?

MmmPancakes

dazzadazza wrote: »

Will I get any attempt marks for the longest day if I attempted to differentiate the function and let it equal to 0, to find maximum day length?

that is actually how you find the longest day, let it equal to zero, solve for x, sub x back into the original equation

randylonghorn

username 2212 wrote: »

Still trying to find the hard question on the OL paper....

MmmPancakes wrote: »

Same :rolleyes:

Stop and actually think ...

If you were finding even an unduly tough OL paper hard, you would hardly be doing HL, would you?

Even teachers generally seem to feel it was a tough paper for the level.

MmmPancakes wrote: »

my bad, feeling a bit bitter/skeptical towards people in the OL thread saying we had it easy and that they would have passed higher but failed ordinary.

Yeah, that's silly, but so is getting annoyed by people getting het up after an exam.

No point in the world the OL and HL people bitching at one another tbh.

dazzadazza

MmmPancakes wrote: »

that is actually how you find the longest day, let it equal to zero, solve for x, sub x back into the original equation

But t turned out to be 0 because it was just a big fraction.

eclipsechaser

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

MmmPancakes

dazzadazza wrote: »

But t turned out to be 0 because it was just a big fraction.

Maybe you made a mistake, anyways, if you let dy/dx = 0 you will get marks for it I'd say

eclipsechaser

Remainder of Section A.

yoyojc

If for a question

You wrote a solution which was incorrect
then beside it retried the q and it was correct

How is that marked? Is it ok to have different attempts? Do they correct the correct part?

I'd appreciate if anyone knows this

sdio

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

Thanks, I've two questions:

4 b) Why did you need to rearrange the series? Can't you just put a=1 and r=w immediately?

5 a) Why is -2 crossed out?

theRB

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

I didn't get the second part of Q5, but for part 3, i made up an f'(x) and let it equal 0 to show I knew what to do and also said the answer was -5.75 because i did it on the calculator. What sort of attempt marks do you think I would get?

eclipsechaser

sdio wrote: »

Thanks, I've two questions:

4 b) Why did you need to rearrange the series? Can't you just put a=1 and r=w immediately?

5 a) Why is -2 crossed out?

4b) Both work. A=1 and R=w also leads to the same answer. Your way is quicker!

5a) I hate to tell people but -2 is an incorrect solution. When you square both sides, it creates an extra solution. If you check both solutions you'll see that -2 doesn't equal root 4. (Technically root of a natural number is always positive). See LC 2002 P1 Q1a for the same type of question. If you got this wrong, don't worry; so did practically everyone else.

theRB wrote: »

I didn't get the second part of Q5, but for part 3, i made up an f'(x) and let it equal 0 to show I knew what to do and also said the answer was -5.75 because i did it on the calculator. What sort of attempt marks do you think I would get?

Writing down f'(x)=0 is likely to get you around 4/10 on its own. However if you got -5.75 and the corresponding y value - despite doing it on a calculator - then you should get full marks if you showed some workings. So long as it doesn't specify a method - and it didn't - you can use trial and error if you show some calculations. That's good hustle considering you got the B part wrong.

sdio

eclipsechaser wrote: »

5a) I hate to tell people but -2 is an incorrect solution. When you square both sides, it creates an extra solution. If you check both solutions you'll see that -2 doesn't equal root 4. (Technically root of a natural number is always positive). See LC 2002 P1 Q1a for the same type of question. If you got this wrong, don't worry; so did practically everyone else.

Thanks, that was a rather sneaky question then.

ParalysedBeaver

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

In 4a, in the second to last line, did you forget to put it all over 26? It seems that's what both numbers above where divided by.

eclipsechaser

ParalysedBeaver wrote: »

In 4a, in the second to last line, did you forget to put it all over 26? It seems that's what both numbers above where divided by.

Yeah, 2nd last line is over 26. (130+26i/26). My final line is the correct answer (5+i). Felt like there might have been a quicker way to solve it but that one works well enough I guess.

dazzadazza

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

Thank you so much you've put my mind at ease I'm confident I got at least 90% in that paper. I now have the necessary motivation to work for p2. Would you mind doing section B when you get a bit of time? Thanks

Cr4pSnip3r

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

I was uncertain about how badly I likely failed before reading that. *sigh*

DarraghF197

eclipsechaser wrote: »

I just did Section A there in case people want to check their answers. I'm a bit tired for Section B. Might do it out tomorrow if people want.

When finding the derivative of the surd in question 5, did you have to put it in its simplest form ie, where the surd is above the line? Made my third part messier than it needed and got me another answer which I crossed out anyways.

And for that root four, because it's an even number, you only have the nonnegative solution? That's annoying, especially since theyre likely to have strict marking schemes after that exam!

Other than that, as expected. So zero is the unofficial official answer! I wrote that answer down, but then did it a different way. Hopefully they'll give me the marks!

Just that surd hiccup and the image for the plane I lost marks for I think/hope.