Maths, Addmaths and Statistics: Post your doubts here!

[Suchal Riaz]

Pk

Just use the class widths that are given. You've divided them incorrectly. Using this you're frequency densities should be:
35-40 : 3
40-45 : 4
45-50 : 6
50-55 : 7
55-60 : 5.6
60-70 : 1.2
The last 4 are correct, just make the correction to the size of the last block and to the first two frequency densities, you're graph will be perfect then.

thanx. Got it. Made error in plotting.
I can never recheck my own graph.

 

[Snowysangel]

Use cosine rule,
ACB = 47.38
Therefore,
ACD = 90 - ACB = 42.62
Using trigonometric ratio,
sin ACD = AD/AC
AD = sin (42.62)(21.3)
AD = 14.43 m

How do u find the angle of elevation of b from e?

 

[Saad Mughal]

How do u find the angle of elevation of b from e?

Angle of Elevation = Angle BEC
If you calculated CE correctly then,
tan BEC = BC/CE
Put the values and calculate the angle, that's your answer.

 

[AbbbbY]

can anyone help me with q 9 b i a
http://papers.xtremepapers.com/CIE/Cambridge International O Level/Mathematics D (Calculator Version) (4024)/4024_s10_qp_21.pdf

tan 45 = Perp / x

So perp = xtan45
and MN = 2xtan45

Edit: You can simplify tan45 (or any other value should the need be). Tan 45 = 1 so MN = 2x.
Is the answer? 2xTan45 and 2x both should be acceptable if I'm not mistaken.

 

[Muqeet Tahir Malik]

While giving answer like of different parts should we round to 3 sig.fig but if exact value on calculator should we write that ,do explain

 

[AbbbbY]

While giving answer like of different parts should we round to 3 sig.fig but if exact value on calculator should we write that ,do explain

What?

If you calculator shows 3.13253q9689
You use 3.133
If the final answer is the said, you write 3.13

If the calculator shows 3.15, obv you'll use 3.15

Only angles (in degrees) are to be given to 1d.p Rad will be 3sf.

 

[Zoya Shahab]

Can someone plz help me with this question.
x^3+ax^2-x+b and x^3+bx^2-5x+3a have a common factor of x+2. find the value of a and b.m
i tried to suppose x+2=0 so x=-2. i substituted this value in the equ to get a-3b=8. so what next?

 

[AbbbbY]

Can someone plz help me with this question.
x^3+ax^2-x+b and x^3+bx^2-5x+3a have a common factor of x+2. find the value of a and b.m
i tried to suppose x+2=0 so x=-2. i substituted this value in the equ to get a-3b=8. so what next?

a= 2
b= -2

Use x = -2 in each equation. Since it's a factor, it'll equal zero.

Then resolve the equation and solve simultaneously.

 

[Suchal Riaz]

Saad Mughal
one more histogram please
i suck at statistics

 

[Saad Mughal]

While giving answer like of different parts should we round to 3 sig.fig but if exact value on calculator should we write that ,do explain

Use 4 significant figures in ALL your working and give ANSWERS to 3 significant figures unless otherwise stated. Give all angles to 1 decimal place.

 

[TheStallion-Reborn]

first, divide the square into quadrants, find area o quadrant 19.63. then divide the top right hand side oval shape into two. in this way quadrant would become a triangle and a half oval. then calculate area of triangle 12.5. subtract the area of tri from quad to get area of half oval. 7.13. then find area of semi circle. 39.27.ssubtract the area of one oval from it to get ans. 39.27-2(7.13) = 25

sorry i didnt get a word.wht r quadrants?

 

[Saad Mughal]

Saad Mughal
one more histogram please
i suck at statistics
View attachment 27499

Yeah, it's correct.
Your drawings are way too light.

 

[Suchal Riaz]

Yeah i made it ligh so it is easier to erase if its wrong.

Yeah, it's correct.
Your drawings are way too light.

One more.

 

[Saad Mughal]

Yeah i made it ligh so it is easier to erase if its wrong.
One more.View attachment 27529

Yeah, it's correct too. Try to rotate the images (using Windows Photo Viewer) before uploading. It's kinda hard to turn my head and check.

 

[danial 234]

sorry i didnt get a word.wht r quadrants?

quadrants are quarter of a circle

 

[Suchal Riaz]

Okay let me see how to rotate image in ios. I m new to ios.

 

[Sikander Khan]

Plz tell me how do we get 2/3 as answer from this |>

 

[TheStallion-Reborn]

first, divide the square into quadrants, find area o quadrant 19.63. then divide the top right hand side oval shape into two. in this way quadrant would become a triangle and a half oval. then calculate area of triangle 12.5. subtract the area of tri from quad to get area of half oval. 7.13. then find area of semi circle. 39.27.ssubtract the area of one oval from it to get ans. 39.27-2(7.13) = 25

so much of an effort for just 1 mark

 

[danial 234]

so much of an effort for just 1 mark

But this JUST one mark can make the A* a distinction. Every mark matters

 

[farhan141]

Plz tell me how do we get 2/3 as answer from this |>View attachment 27531

12^1/2
---------
3^3/2

= 4^1/2
---------
1^3/2

= 2
----
1

= 2