Mathematics Question Thread

[Nialllovespie]

Can anyone help me with this question please?

A circle with circumference 124mm has a chord cut off it that subtends an angle of 40 degrees at the centre. Find the length of the arc cut of by the chord.

Thanks so much!

[RuiAce]

Can anyone help me with this question please?

A circle with circumference 124mm has a chord cut off it that subtends an angle of 40 degrees at the centre. Find the length of the arc cut of by the chord.

Thanks so much!

[Shadowxo]

Can anyone help me with this question please?

A circle with circumference 124mm has a chord cut off it that subtends an angle of 40 degrees at the centre. Find the length of the arc cut of by the chord.

Thanks so much!

Great answer by RuiAce but here's an alternate way of doing it:
the length of the arc is a fraction of the circumference
The fraction is 40/360 = 1/9
So the length of the arc is 1/9th of the circumference,
= 1/9 * 124 = 124/9mm

Hope this helps

[asd987]

Hi, Can i get some help with this question please:
Find the exact area between the curve y=1/x , the x axis and the lines y=x and x=2 in the first quadrant

[RuiAce]

Hi, Can i get some help with this question please:
Find the exact area between the curve y=1/x , the x axis and the lines y=x and x=2 in the first quadrant

[katnisschung]

clarification of integration terminology..

just want to check that i've got this stuff covered.

1. ordinates=function vales (i interpret this as how many individual values there actually are)
2. (sub) intervals= how many trapeziums there are (specific to the trapezium rule)
3. applications (how many times you apply the rule)

so for this questiton

b) integrate log 10 x dx (between 10 and 1) using 4 function values
using the trapezium rule...

so this would have 3 applications, function values being (1, 4, 7, 10)
correct?

thanks!

[RuiAce]

clarification of integration terminology..

just want to check that i've got this stuff covered.

1. ordinates=function vales (i interpret this as how many individual values there actually are)
2. (sub) intervals= how many trapeziums there are (specific to the trapezium rule)
3. applications (how many times you apply the rule)

so for this questiton

b) integrate log 10 x dx (between 10 and 1) using 4 function values
using the trapezium rule...

so this would have 3 applications, function values being (1, 4, 7, 10)
correct?

thanks!

Looks good

[kylesara]

Hi, i need help with a question from hw.

Find the areas enclosed by the curves x=y^2 and y=x^2

Thanks!

[jakesilove]

Hi, i need help with a question from hw.

Find the areas enclosed by the curves x=y^2 and y=x^2

Thanks!

Hey! First, we need to find both equations in terms of x.





We want the area enclosed. The only way to do that is to draw the function, so we know exactly what's going on. I'll leave that to you.

There is an area enclosed between y=x^2 and the positive part of the other function. By sketching, we know that y=x^2 is on the bottom of the enclosed section, therefore to find the area we simply subtract the bottom function from the top, and integrate. Clearly, the points of intersection are 0 and 1.



You should be able to do the rest!

[brokenboxes]

Hey there

This may seem like a really foolish and unusual question but I have an infamous reputation for making silly mistakes in exams. Whether it be forgetting to change a sign or accidentally writing a 2 instead of a 7, I always get caught up by these despite the amount of practice I do. Would you have any tips for dealing with this?

Thank you

[RuiAce]

Hey there

This may seem like a really foolish and unusual question but I have an infamous reputation for making silly mistakes in exams. Whether it be forgetting to change a sign or accidentally writing a 2 instead of a 7, I always get caught up by these despite the amount of practice I do. Would you have any tips for dealing with this?

Thank you

Well the answer to this question depends on if you make them AS you practice, or ONLY in the exam.

If you make the mistakes AS you practice, then the answer is somewhat simple. It means that your practice hasn't been sufficiently effective. This may or may not imply poor quantity of practice as well, but it means you have to look out more when you're practicing. Check your working every 5 or so lines, instead of at the end. And don't try to do too many things at once if it's too overloading (e.g. use trig identities on one side but then a lot of algebra on the other).

If you only bump into this issue in the exam, then there may be the exam stress factor fueling it. The first thing to do is to make sure you're not stressed and focused on the question. Similar to the above, check your working every 5 or so lines. But you should consider memorising this list that Jamon just has very handy up his sleeve. When going through your working out, recite all the steps you did (quickly though, because you don't want to go into time trouble) and make sure NONE of that nuisance happens. And for things such as writing a wrong number, I always think the number in my head. I think "seven-hundred-and-twenty-five" as I write 725. Like, not just process the number, think it as if I had to force it into my brain. (Also, make sure there's no handwriting problems.)

On top of Jamon's list, write down every single silly mistake you've encountered. You can make a mistake, then forget you ever made it and discard the entire thought. List them out, and have them laid out right in front of you when you do practice papers, so that they are always ringing a bell.

[jakesilove]

Hey there

This may seem like a really foolish and unusual question but I have an infamous reputation for making silly mistakes in exams. Whether it be forgetting to change a sign or accidentally writing a 2 instead of a 7, I always get caught up by these despite the amount of practice I do. Would you have any tips for dealing with this?

Thank you

Hey! Welcome to the forums!

I was absolutely notorious for the same thing. I'd smash out a question, and invariably forget a minus somewhere and lose a mark. However, this only really plagued me for the start of my 2U course. I managed to ween myself out of silly mistakes (at least, as much as you can; you'll always make one of two in every exam!).

There's really only two things you can do to get over silly mistakes. One is sheer attrition. Do a billion questions. Then do a billion more. The more you practice, the less likely you are to make stupid mistakes. It's just probability; the better you understand the content, the less likely you are to make a stupid mistake.

The second way I made sure I made as few silly mistakes as possible was by writing them out. I would keep a list of mistakes that I consistently made, and I'd try to make the list funny, sweary, and concise. Then, I'd have those sorts of mistakes in my head as I sat a paper. Keep updated the list, and you'll find yourself needing it less and less (which is the idea).

Really great question! Let me know if you need anything else

[jakesilove]

Well the answer to this question depends on if you make them AS you practice, or ONLY in the exam.

If you make the mistakes AS you practice, then the answer is somewhat simple. It means that your practice hasn't been sufficiently effective. This may or may not imply poor quantity of practice as well, but it means you have to look out more when you're practicing. Check your working every 5 or so lines, instead of at the end. And don't try to do too many things at once if it's too overloading (e.g. use trig identities on one side but then a lot of algebra on the other).

If you only bump into this issue in the exam, then there may be the exam stress factor fueling it. The first thing to do is to make sure you're not stressed and focused on the question. Similar to the above, check your working every 5 or so lines. But you should consider memorising this list that Jamon just has very handy up his sleeve. When going through your working out, recite all the steps you did (quickly though, because you don't want to go into time trouble) and make sure NONE of that nuisance happens. And for things such as writing a wrong number, I always think the number in my head. I think "seven-hundred-and-twenty-five" as I write 725. Like, not just process the number, think it as if I had to force it into my brain. (Also, make sure there's no handwriting problems.)

On top of Jamon's list, write down every single silly mistake you've encountered. You can make a mistake, then forget you ever made it and discard the entire thought. List them out, and have them laid out right in front of you when you do practice papers, so that they are always ringing a bell.

Typical Rui, beating me to the punch

[biffi023]

What is the best way others have found to study Mathematics?! I have so much trouble remembering the formulas etc of older topics once we have been doing the more recent ones for a while!! (I do Mathematics but struggle with it!  ) There is so much content that just physically remembering processes (especially when they didnt TRULY stick in your head when you learnt them) can get so confusing!  Also, how do you overcome the way that different teachers and exam setters can word questions just slightly different enough to throw you??

[RuiAce]

What is the best way others have found to study Mathematics?! I have so much trouble remembering the formulas etc of older topics once we have been doing the more recent ones for a while!! (I do Mathematics but struggle with it!  ) There is so much content that just physically remembering processes (especially when they didnt TRULY stick in your head when you learnt them) can get so confusing!  Also, how do you overcome the way that different teachers and exam setters can word questions just slightly different enough to throw you??

Simply memorising formulas is not enough. Everyone will say this - you must be consistently doing past papers and more past papers to study for mathematics. Maths is a skills-based course; hardly anything simply content based will appear on the day. You cannot prepare for an exam by simply going off content. You need to prepare for the exam by doing old past papers, because only they reflect what your exam will be like, and thus what you should be prepared for. By doing past papers, you train your brain to think the way you're expected to be thinking.

Do not stop the past papers. And do a whole variety of them so that you maximise your exposure to all the possible things they can ask.