Mathematics: Post your doubts here!

[AAnsarii]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_4.pdf
7 a i. hw do u solve dat? plz hlp

 

[diamondsky]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_4.pdf
7 a i. hw do u solve dat? plz hlp

der u go. it was easy

 

[Saahil Parikh]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_4.pdf
7 a i. hw do u solve dat? plz hlp

54+21+8a+45/ 17+a=7.2 (mean = sigma fx/sigma f)
120+8a=7.2(17+a)
120+8a= 122.4+7.2a
2.4=0.8a
a= 2.4/0.8= 3

 

[sparsha.mehta]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w06_qp_4.pdf
7 a i. hw do u solve dat?

Is the ans. 3.00

 

[sparsha.mehta]

Please visit http://drtayeb.com

I visited there for ict 2012 files...
Awesome site

 

[NyaMah]

p²x-4q²x How would I factorise fully? I know its got something to do with the form (a+b)² but I dont know what that is ? could you please explain to me what the form (a+b)² is and what it does?

 

[diamondsky]

p²x-4q²x How would I factorise fully? I know its got something to do with the form (a+b)² but I dont know what that is ? could you please explain to me what the form (a+b)² is and what it does?

dis is actually d form a²-b²
remove x out so:
x(p² - (2q)²)
= (p-2q)(p+2q)

for d second qns
(a+b)² = a² + 2ab + b²

 

[Igcse stuff]

how do you solve these questions?
1. The volume of the planet Uranus is 64 times the volume of the planet Earth.
Assuming that Uranus and Earth are geometrically similar, calculate the ratio of
Surface area of Uranus : Surface area of Earth in the form n : 1.
AND
2.The speed of light is 300 000 kilometres per second.
(a) Write 300 000 in standard form.
Answer (a) ......................................................... P I
(b) The nearest star, Proxima Centauri, is 4.2 light years from the Sun. One light year is the distance
light travels in 365 days. Calculate the distance of Proxima Centauri from the Sun.
Give your answer in kilometres in standard form.
Answer (b) ................................................... km 111
FROM A PAST PAPER

 

[diamondsky]

how do you solve these questions?
1. The volume of the planet Uranus is 64 times the volume of the planet Earth.
Assuming that Uranus and Earth are geometrically similar, calculate the ratio of
Surface area of Uranus : Surface area of Earth in the form n : 1.
AND
2.The speed of light is 300 000 kilometres per second.
(a) Write 300 000 in standard form.
Answer (a) ......................................................... P I
(b) The nearest star, Proxima Centauri, is 4.2 light years from the Sun. One light year is the distance
light travels in 365 days. Calculate the distance of Proxima Centauri from the Sun.
Give your answer in kilometres in standard form.
Answer (b) ................................................... km 111
FROM A PAST PAPER

1._/64 = 4
therefore ratio is 4:1
4^2:1^2
n=16
2. a) 3 x 10^5
b)1 light year = 300000 x 60 x 60 x 24 x 365 = 9.4608 x 10 ^12 km
4.2 light years = 3.97 x 10^10 km!
omg dats a lot of distance!!!

 

[Igcse stuff]

thanks a lot.... however, I'm not so clear about how you got the two 60*60 in your working, under questoin two

 

[diamondsky]

thanks a lot.... however, I'm not so clear about how you got the two 60*60 in your working, under questoin two

1 min = 60 s
1 hr = 60 min
1 hr = 60 x 60 s

 

[Igcse stuff]

1 min = 60 s
1 hr = 60 min
1 hr = 60 x 60 s

alright it's clear now, thanks.
do you have notes on sequence and series?

 

[sparsha.mehta]

alright it's clear now, thanks.
do you have notes on sequence and series?

I swear sequencing in maths is time consuming???

 

[Igcse stuff]

I swear sequencing in maths is time consuming???

yeah, your right it's time consuming, that's why I'm looking for notes. maybe they can have faster and easier techniques of solving sequences in a shorter period of time

 

[Igcse stuff]

can someone help with Q6(b) and Q7(e)iii

 

[diamondsky]

can someone help with Q6(b) and Q7(e)iii

6.b) 1/2*14*19 + 14*36 + 23.6*36 + 19*36 = 2303.6 cm2
7.e)iii) use ur graph to find out wer d 2 lines intersect

 

[Igcse stuff]

6.b) 1/2*14*19 + 14*36 + 23.6*36 + 19*36 = 2303.6 cm2
7.e)iii) use ur graph to find out wer d 2 lines intersect

so total surface area is simply the total summation of he areas, it doesn't have a definite formula right?
and for question 6(e), i checked the answer and the only way to find the distance of the line CE is by using Pythagoras theorem. however, i'm wondering why Pythagoras theorem has been used because the angle CBE is not at 90 degrees, from the angle at which we are viewing the prism
THANKS BY THE WAY

 

[Kieran]

Can someone please help me by explaining step by step how to do these questions from 0580 may/june 2012 paper 21?
Questions 17, 15b and 20.
Thanks!

 

[Bob takoyaki]

How do you do question 10 http://books.google.co.nz/books?id=...nd that the initial deceleration is 4&f=false

 

[diamondsky]

Can someone please help me by explaining step by step how to do these questions from 0580 may/june 2012 paper 21?
Questions 17, 15b and 20.
Thanks!

15b) 1:500000(cm)
=> 1:5(km)
square it
=>1:25(fr area)
12:x
x=12 x 25 = 300

17)c(w-3)=4+w
=>cw-3c=4+w
=>cw-w=4+3c
=>w(c-1)=4+3c
=>w=4+3c/c-1

20) angle OTP = 90
tan 78 = PT/5
PT = tan 78 x 5 = 23.52 cm
angle ROT(reflex) = 360 - (78 + 78)
= 204
major arc = 204/360 x 2 (pi) x 5
=17.80
=>length of rope = 23.52 x 2 + 17.80 = 64.8