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March 29, 2024, 04:18:47 am

Author Topic: Mathematics Question Thread  (Read 1296805 times)  Share 

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jamonwindeyer

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Re: Mathematics Question Thread
« Reply #795 on: October 21, 2016, 10:35:47 am »
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Its still confusing...

All good! So:



For Pat to win on the second throw, he has to not win on his first throw, and then win on his second:



So the answer to B is:



If we went to three throws, it would be similar; he needs to lose TWO throws and then win on his third:



See the pattern? We have a geometric series forming, \(a=\frac{1}{36}\) and \(r=\frac{35}{36}\) ;D

Now this value of r lets us take an infinite series and get a value; so use that formula for infinite series from your reference sheet with those values, and that is how you answer Part C ;D

Blissfulmelodii

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Re: Mathematics Question Thread
« Reply #796 on: October 21, 2016, 10:38:43 am »
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Hi, I have a couple of questions:
1. If the question doesn't specify do we leave answer in exact form or decimal and would we get marked down for either?
2. If we answer a question and you could take out a common factor - should you do that or not - some past paper answers do it and some don't and would we get marked down either way?
3. What are acceptable abbreviations for proving geometrical questions?
4. do we leave our answer in improper fraction or mixed numeral - if not specified in question?
5. If not specified in question how many decimals should you round to?

Thank You!

From what I have been told by my teachers if the question doesn't specify you should always leave it in exact form but they probably won't mark you down for putting it into decimal form

Again with the second question, if its not specifies then they won't take marks of for how you have left it but they usually always want to simplified answer which mean taking out common factors and factorizing.

For the third question I've heard mixed fractions are better but again if not specified either works

And for your last question I would personally round to about 3 or 4 to keep accuracy.

Hope this helps
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jamonwindeyer

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Re: Mathematics Question Thread
« Reply #797 on: October 21, 2016, 10:38:57 am »
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Hi, I have a couple of questions:
1. If the question doesn't specify do we leave answer in exact form or decimal and would we get marked down for either?
2. If we answer a question and you could take out a common factor - should you do that or not - some past paper answers do it and some don't and would we get marked down either way?
3. What are acceptable abbreviations for proving geometrical questions?
4. do we leave our answer in improper fraction or mixed numeral - if not specified in question?
5. If not specified in question how many decimals should you round to?

Thank You!

1. If it doesn't specify and you have the capability, exact form.
2. Factorising your final answer is something you can do, but it is unnecessary; you won't get marked down as long as you factorise don't divide
3. \(\Delta\) for a triangle, \\ for parallel lines, and the congruency and similarity symbols to name a few. Try not to abbreviate words like "isosceles" unless you are short on time (you will probably be fine even if you do)
4. Improper Fraction is nicer imo, but BOSTES does use mixed numeral at times. Either or :)
5. If not specified, pick a sensible number. General rule is the most amount of decimal places used in the question (but then I usually just add one to that just to be safe) :)
« Last Edit: October 21, 2016, 10:43:34 am by jamonwindeyer »

RuiAce

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Re: Mathematics Question Thread
« Reply #798 on: October 21, 2016, 10:40:32 am »
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Some chaos occurs with mixed numerals. Don't smack me Jamon but I need to emphasise your point on this one :P preferably improper fractions please.

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Re: Mathematics Question Thread
« Reply #799 on: October 21, 2016, 10:40:47 am »
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Hey!
Just wondering, would changing our calculators to radians by default change our calculations for other answers that don't need radians? I always have mine in degrees and change it to radians whenever i need it   ???

Thanks!

Yes, you need to be careful about this because it does affect your answers for, say, geometry questions that use degrees.

Leave your calculator in radians, then swap to degrees as soon as you see the degree symbol, then swap back as soon as that question is done. That's what I recommend since radians is the default unit of angular measure ;D

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Re: Mathematics Question Thread
« Reply #800 on: October 21, 2016, 10:41:43 am »
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Some chaos occurs with mixed numerals. Don't smack me Jamon but I need to emphasise your point on this one :P preferably improper fractions please.

Happy to be emphasised; it does create room for more error! ;D (although BOSTES uses them in sample solutions, I never did, and was fine. Don't create more work for yourself) :)

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Re: Mathematics Question Thread
« Reply #801 on: October 21, 2016, 10:58:02 am »
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Good luck to everyone who is sitting the exam today  ;D (although I'm probably the one that's going to need it  ;) )
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Re: Mathematics Question Thread
« Reply #802 on: October 21, 2016, 11:00:46 am »
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Good luck to everyone who is sitting the exam today  ;D (although I'm probably the one that's going to need it  ;) )
Have faith, don't imply that about yourself

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Re: Mathematics Question Thread
« Reply #803 on: October 21, 2016, 11:20:51 am »
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Hey guys,

Just a question with rates of change.
If t equals something like 152.65 months, what is your final answer if it says when does P = x, occur. Do we leave it as a decimal? Or round to a month?
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MysteryMarker

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Re: Mathematics Question Thread
« Reply #804 on: October 21, 2016, 11:21:17 am »
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Hey guys, this is more just a rule that i'm asking, but I remember that when there are parallel lines and two transversal intersect them, the ration between the two transversals are equal or something? Could someone just rephrase that properly or enlighten me on whether that is the correct rule?

Cheers, ALSO GOOD LUCK PEEPS and a MASSIVE shoutout to all the moderators and members that make revising for 2U that much easier. :P

RuiAce

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Re: Mathematics Question Thread
« Reply #805 on: October 21, 2016, 11:22:51 am »
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Hey guys,

Just a question with rates of change.
If t equals something like 152.65 months, what is your final answer if it says when does P = x, occur. Do we leave it as a decimal? Or round to a month?
I recommend rounding so that your units are consistent, but I think unless they explicitly say how many years and months it isn't that much of a concern to use a decimal answer.

If they say explicitly how many years and months then you have to answer the question.

I'll let others comment on this one as well

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Re: Mathematics Question Thread
« Reply #806 on: October 21, 2016, 11:24:25 am »
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is using the @ symbol ok?

RuiAce

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Re: Mathematics Question Thread
« Reply #807 on: October 21, 2016, 11:24:55 am »
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Hey guys, this is more just a rule that i'm asking, but I remember that when there are parallel lines and two transversal intersect them, the ration between the two transversals are equal or something? Could someone just rephrase that properly or enlighten me on whether that is the correct rule?

Cheers, ALSO GOOD LUCK PEEPS and a MASSIVE shoutout to all the moderators and members that make revising for 2U that much easier. :P
You can call it "Ratio of intercepts on transversals of parallel lines" when you write out the ratio relevant. Or just "intercepts on transversals of parallel lines"

TBH - I've never needed that theorem yet even though it's in the course

Glad we've helped ya

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Re: Mathematics Question Thread
« Reply #808 on: October 21, 2016, 11:25:35 am »
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is using the @ symbol ok?

In what sense? But probably not a good idea
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RuiAce

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Re: Mathematics Question Thread
« Reply #809 on: October 21, 2016, 11:26:09 am »
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is using the @ symbol ok?
That just stands for "at". It's not too much of a hassle to write two letters lol

When do you need it in 2/4U though? I don't really recall any scenario I came across it