2 unit paper (3 Viewers)

[candyman]

Yeah period of tan(3x) is pi/3.

InteGrand would you be able to verify h = xy or h = y/x for q5cii ?

Thank you

 

[piethepker]

Awesome !

Does anyone know the solution to Q16 b) iv? Probably the most conflicting one in my cohort.

And I'm a little unsure with the wording of Q15 b) ii but I just left my answer as n = 10 because n = 11 is like 0.76 - Have a bad feeling its n = 11. But hopefully I get some marks for my working out?

Fairly sure its n=11 because if you sub in n=10 it was like 74.7%

 

[pikachu975]

Awesome !

Does anyone know the solution to Q16 b) iv? Probably the most conflicting one in my cohort.

And I'm a little unsure with the wording of Q15 b) ii but I just left my answer as n = 10 because n = 11 is like 0.76 - Have a bad feeling its n = 11. But hopefully I get some marks for my working out?

I got 10 as well idk though I think it's wrong.

For the last question with y = 100, did we have to test the nature? I didn't, rip

 

[WrittenLoveLetters]

Fairly sure its n=11 because if you sub in n=10 it was like 74.7%

Sigh yeah. I slowly read the question over and over and finally got what it means. I definitely won't get the mark for the correct answer so hopefully I get 2/3 for my solution - because I actually got 10.somethingsomething and sat there just thinking which one to even pick because the question was like what?

 

[pikachu975]

Sigh yeah. I slowly read the question over and over and finally got what it means. I definitely won't get the mark for the correct answer so hopefully I get 2/3 for my solution - because I actually got 10.somethingsomething and sat there just thinking which one to even pick because the question was like what?

My friend said it was 12 because the question said "before the nth roll" so since it was the 11th roll, it has to be before the 12th one.

 

[trecex1]

Sigh yeah. I slowly read the question over and over and finally got what it means. I definitely won't get the mark for the correct answer so hopefully I get 2/3 for my solution - because I actually got 10.somethingsomething and sat there just thinking which one to even pick because the question was like what?

99.95% sure it's n=12

Anyone else equate expressions to find the height of the triangle in the tile question? I got 69 degrees but literally just realised you can cos rule it and get it in 3 lines

 

[pikachu975]

99.95% sure it's n=12

Anyone else equate expressions to find the height of the triangle in the tile question? I got 69 degrees but literally just realised you can cos rule it and get it in 3 lines

I did cos rule and got 69 degrees.

 

[InteGrand]

Yeah it's definitely strictly before the n-th roll, e.g. looking at the first part of that question, they asked for before the 4th roll and went up to roll #3.

 

[Esse]

Sigh, out of 3 what will i receive for putting n = 11

 

[pikachu975]

Please tell me we didn't need to test for the last question y = 100 lol

 

[InteGrand]

Please tell me we didn't need to test for the last question y = 100 lol

I got 10 as well idk though I think it's wrong.

For the last question with y = 100, did we have to test the nature? I didn't, rip

What method did you use (sorry if you said this above already, I haven't followed this thread too closely)? If you did the parabola method I mentioned before, it's self-evident really. Plus the question's wording makes it sounds like they let you assume it (if I recall the question correctly).

Looking back at the Q. now, it's two marks. So at least you should have some working out, and the answer. It'd probably be best to justify when the maximum occurs (e.g. concave down parabola). If you use this parabola method, you don't need to test, just need to do something like mention it's a concave down parabola, so it's maxed at the vertex etc.

 

[Nexa579]

Yeah it's definitely strictly before the n-th roll, e.g. looking at the first part of that question, they asked for before the 4th roll and went up to roll #3.

I interpreted the question as:

What is the smallest value of n for which the probability of the game ending, before the nth roll is more than 3/4?

In this case n = 10. Which is what I put..

--

So what you're saying is that we're supposed to read it as:

What is the smallest value of n for which the probability of the game ending before the nth roll, is more than 3/4?

 

[Speed6]

Are there any solutions which have been released for the 2U paper?

 

[InteGrand]

I interpreted the question as:

What is the smallest value of n for which the probability of the game ending, before the nth roll is more than 3/4?

In this case n = 10. Which is what I put..

--

So what you're saying is that we're supposed to read it as:

What is the smallest value of n for which the probability of the game ending before the nth roll, is more than 3/4?

What do you mean by the first comma placement? That makes it sound like "before the nth roll is more than 3/4", as in somehow the nth roll can be more than three-quarters, which is nonsensical of course.

Basically it's before like strictly before. I.e. find the smallest value of n such that p_n > 3/4, where p_n is the probability the game ends on one of rolls #1,2,...,n-1.

 

[Nexa579]

What do you mean by the first comma placement? That makes it sound like "before the nth roll is more than 3/4", as in somehow the nth roll can be more than three-quarters, which is nonsensical of course.

When n = 10, p() = 0.74...
When n = 11, p() = 0.76...
So when n = 10, the probability is less than 3/4.

 

[InteGrand]

When n = 10, p() = 0.74...
When n = 11, p() = 0.76...
So when n = 10, the probability is less than 3/4.

What's your definition of n and p()? In the Q., we're saying the game ended at or before roll#(n-1). So if n = 10, you'd need to have gone up to roll #9.

 

[trecex1]

When n = 10, p() = 0.74...
When n = 11, p() = 0.76...
So when n = 10, the probability is less than 3/4.

No it's not. You did something wrong in your working, when n=12 then p> 3/4

 

[InteGrand]

The reason is we're not allowed to link that page or type its name on BOS.

 

[Esse]

Haha sorry . How many marks would I lose for stating n as 11, and using the formula where r is to the power of n not n-1

 

[InteGrand]

Haha sorry . How many marks would I lose for stating n as 11, and using the formula where r is to the power of n not n-1

I don't know but it seems to just be a misinterpretation of the wording/requirement of the question (although the first part of the Q. should've made it clear what the interpretation is). So you should at least get some marks (guessing). Maybe lose 1? You could ask Carrotsticks for his opinion.