Maths, Addmaths and Statistics: Post your doubts here!

[scouserlfc]

NO never u are always given in the question the length only u have to use a scale like 1 cm for 5 m depending on what dimensions u are drawing !

 

[SalmanPakRocks]

exactly.

 

[awaisbuttrocksCIE]

http://www.xtremepapers.com/CIE/Cambridge O Levels/4024 - Mathematics/4024_s08_qp_1.pdf


Solve q24 please?

 

[SalmanPakRocks]

http://www.xtremepapers.com/CIE/Cambridge O Levels/4024 - Mathematics/4024_s08_qp_1.pdf


Solve q24 please?

Ok so this is group data as we know the frequency, anyhow here is how it will be done;
i) So use this formula since the sum of frequency is even
N/2 i.e: 50/2 = 25
ok now see at place is 25 comming, start counting from the beginning and stop when u reached 25,
therefore: 10 + 11 + 8 = 29. As this has 25th value in it, this must be the median class, therefore the median is 2.

ii) Mean for group = Sum of Fx/Sum of F
multiply frequecy with x to find fx and then calculate the sum of all then divide it with 50 (cuz its the sum of frequecy)

iii) simple:
7/50 x 6/49

 

[scouserlfc]

http://www.xtremepapers.com/CIE/Cambridge O Levels/4024 - Mathematics/4024_s08_qp_1.pdf


Solve q24 please?

I hope the b part of thre ques u know if not we will help u !

 

[SalmanPakRocks]

sure.

 

[awaisbuttrocksCIE]

Ok so this is group data as we know the frequency, anyhow here is how it will be done;
i) So use this formula since the sum of frequency is even
N/2 i.e: 50/2 = 25
ok now see at place is 25 comming, start counting from the beginning and stop when u reached 25,
therefore: 10 + 11 + 8 = 29. As this has 25th value in it, this must be the median class, therefore the median is 2.

ii) Mean for group = Sum of Fx/Sum of F
multiply frequecy with x to find fx and then calculate the sum of all then divide it with 50 (cuz its the sum of frequecy)

iii) simple:
7/50 x 6/49

thanks salman...

 

[awaisbuttrocksCIE]

I hope the b part of thre ques u know if not we will help u !

no worries now...BTW thanks

 

[SalmanPakRocks]

no problem.

 

[scouserlfc]

No problem !

 

[nightmaressana]

AoA!
Finding the gradient of a curve at a given point using graphical means will not bear an accurate answer. Fortunately, CIE always specifies a range in which your answer must lie so you don't need to worry about it....much . Ways to improve your gradient calculation:
-> Ensure that the tangent touches the curve at a SINGLE point.
-> Draw a tangent that covers at least half of your graph. In fact, the larger the triangle for calculating the gradient, the more accurate the answer. :wink:
-> Use dotted lines for drawing the other sides of the triangle (the tangent is the hypotenuse) and mention the coordinates of the vertices on your graph. Doing so will reduce chances of error while calculating the gradient.

the method we've been taught, can you tell if its ok?
we draw a tangent which touches the curve at a single point and then, we note the coordinates where the tangent cuts the x and y axis and then use the formula y2-y1/x2-x1? if its correct, i dont know why my gradient comes either one or two digits smaller or greater... :-S

 

[abcde]

the method we've been taught, can you tell if its ok?
we draw a tangent which touches the curve at a single point and then, we note the coordinates where the tangent cuts the x and y axis and then use the formula y2-y1/x2-x1? if its correct, i dont know why my gradient comes either one or two digits smaller or greater... :-S

It is correct although it's not necessary to use the coordinates where the tangent intersects the axes. You can draw a tangent as large as possible and use the coordinates of any two points on it to calculate the gradient. As I said earlier, the further apart the two points, the more accurate will be your result. And your gradient is prone to be non-exact. After all, you're using a graphical method. As long as your answer is within the range CIE specifies in mark schemes, you're good. No worries. (P.S. You won't find a range in the book answers probably. I'm talking about the mark schemes.)

 

[Anon]

the method we've been taught, can you tell if its ok?
we draw a tangent which touches the curve at a single point and then, we note the coordinates where the tangent cuts the x and y axis and then use the formula y2-y1/x2-x1? if its correct, i dont know why my gradient comes either one or two digits smaller or greater... :-S

Or like I said,
use derivation to sort of brute out the answer before taking it out...

Then make sure your ans is somwhere near it..

 

[scouserlfc]

Or like I said,
use derivation to sort of brute out the answer before taking it out...

Then make sure your ans is somwhere near it..

Oh cmon dude this is maths aint it so u wont have an equation to derivate or integrate and even if u make it ur self u might be in trouble if u get a wrong answer but definitely a good idea !

 

[abcde]

Oh cmon dude this is maths aint it so u wont have an equation to derivate or integrate and even if u make it ur self u might be in trouble if u get a wrong answer but definitely a good idea !

We don't need to 'make' an equation. It is always given in such questions!

 

[Anon]

Even those who are pure Math students, they can simply learn how to find derivative in calculator..
We just need to type in the equation and the x coordinate, and voila!

 

[scouserlfc]

yeah then ill definitely use it for checking my answer but do u guys believe that u are allowed to use add maths in maths,i know we can use maths work in add maths but i was warned always not to use the add maths work in maths ?? so what do u say !

 

[abcde]

yeah then ill definitely use it for checking my answer but do u guys believe that u are allowed to use add maths in maths,i know we can use maths work in add maths but i was warned always not to use the add maths work in maths ?? so what do u say !

Warned by whom? The agency that secretly peers into students' minds and declares it unlawful to use Add-Maths in Maths because Add-Maths is only true and valid when you're attempting an Add-Maths paper and not elsewhere? -.- Mathematical strategies, as long as they are correct, can and should be used anywhere possible. Normally, you will not be expected and/or required to use strategies in Maths 4024 that are not part of the sy. But if you know something that verifies your answer, would you rather have your answer verified or believe anyone's dogmatic claim that bereaves you from the satisfaction of full assurance?

 

[scouserlfc]

Warned by whom? The agency that secretly peers into students' minds and declares it unlawful to use Add-Maths in Maths because Add-Maths is only true and valid when you're attempting an Add-Maths paper and not elsewhere? -.- Mathematical strategies, as long as they are correct, can and should be used anywhere possible. Normally, you will not be expected and/or required to use strategies in Maths 4024 that are not part of the sy. But if you know something that verifies your answer, would you rather have your answer verified or believe anyone's dogmatic claim that bereaves you from the satisfaction of full assurance?

YEAH ill use it but only for verification and not for working as its not part of the syllabus !
Is that good ! BTW a teacher told me !

 

[Anon]

And who told you to do this in the actual solution?
Do it in rough somewhere, Blank Page perhaps.