Mathematics: Post your doubts here!

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Math Angel.. Please give me some tough questions!!..

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

how's ur performance in maths??and for which topic do u need questions??

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

I have so much revision to do and 2 days left =S

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Let me know if u r struck with any question...i will try to help u as soon as possible

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

ill probably get stuck on fractions and transformations!

i just dont get how you can find the transformation vector using two dots on the graph and moving them lol. you explained them here so i'll read them later

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

yeah sure anything else..do not hesitate

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

how's ur performance in maths??and for which topic do u need questions??

Its of average.. I gt 89% in my last exam

I'm having problem in Mensuration, Probability ( Infact my worst topic) AND VECTORS

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

so let me give u one question for mensuration...this is a question made by me!!

Q: A toy is made by cone and cylinder joined together,each of radius 4 cm. The height of the TOY is 24cm and the height of the CONE is 13cm.

(a)Calculate the total surface area of the toy. [4]

(b)The cost of painting 1cm^2 is $0.76.Find the cost of painting the toy. [1]

(c)Calculate the volume of the toy. [3]

(d)The toy is immersed in a cylindrical container of radius 7 cm containing water.Find the rise in water level. [3]

Note:Let me know if u want a figure.....

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

a.
For the cone
TSA = π * 4 ( 13.6 + 4 )
= 221.2 cm2
Cylinder
LSA= Perimeter of Cross section * length
25.1 * 11
276.1 cm2
TSA= 276.1 + 2 ( 50.3)
= 376.7 cm2
TSA of the Toy = 221.2 cm2 + 376.7 cm2
= 597.9cm2

b.
1cm2 0.76
597.9 x

x =$454.40

c. Volume of Cone=

1/3 * base area * height

1/3 * 50.3 * 13
=217.8 cm3

Volume of Cylinder:
π * r2* h
= 552.9cm3

Total= 770.7 cm3

d. Is the answer 5cm?

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Actually i have lostthe paper where i had written the answers(actually i made this question in the beginning of the year)...i will solve it tomorrow again InshAllah and let u know whether u have done it right or not! by the way did u find it easy??

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Actually i have lostthe paper where i had written the answers(actually i made this question in the beginning of the year)...i will solve it tomorrow again InshAllah and let u know whether u have done it right or not! by the way did u find it easy??

I had to struggle.. This TSA and LSA is not my thing,. I will never get it right!

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Oh so i checked ur answers now only....ur ans. to (a) is wrong and bcoz of that (b) is wrong too!
(c) and (d) are correct!!
Now i won't tell ur mistake ...it's a small mistake due to carelessness...worry not i have reached here after doing all possible silly mistakes
Anyway try drawing the figure and solving it again...then i will tell u what u shud take care of!!Anyway just try once again
C u tomorrow

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

We don't have to multiply by two right!

a.
For the cone
TSA = π * 4 ( 13.6 + 4 )
= 221.2 cm2
Cylinder
LSA= Perimeter of Cross section * length
25.1 * 11
276.1 cm2
TSA= 276.1 + 50.3
= 326.4
TSA of the Toy = 221.2 cm2 + 326.4 cm2
= 547.6cm2

b.
1cm2 0.76
547.5 x

x =$416.1

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

How du u expand a2 + b2 ?

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Guys, i need the syllabus for this exam! Extended 0580! also any notes will be appreciated

 

[jazzangel16]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

See that

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

wow, if i had known about this site i would have come here sooner! got introduced by a pastpaper my school gave that had this site's watermark

thanks

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

Any resources on matrices and transformation? That seems to be all I'm struggling with

 

[XPFMember]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

We don't have to multiply by two right!

a.
For the cone
TSA = π * 4 ( 13.6 + 4 )
= 221.2 cm2
Cylinder
LSA= Perimeter of Cross section * length
25.1 * 11
276.1 cm2
TSA= 276.1 + 50.3
= 326.4
TSA of the Toy = 221.2 cm2 + 326.4 cm2
= 547.6cm2

b.
1cm2 0.76
547.5 x

x =$416.1

Assalamoalaikum!!
Actually one mistake u found....i didnt notice that u have written the formula of cone wrong!! n * r * l and this l is the slant height!!u find it using the pythagoras theorem!!
The correct answer for total surface area is 498 cm2

How du u expand a2 + b2 ?

u cannot expand ...u can actually factorise it (a + b)(a - b)

Any resources on matrices and transformation? That seems to be all I'm struggling with

check pg 2 and 3 of this thread!

 

[mimmi]

Re: IGCSE Maths Tips nov.2010!Confused!have questions?Post h

guys, is the formula to find midpoint:

((x2 + x1)/2) , (y2 + y1)/2)?

and the formula to find the gradient:

(x2 - x1)/(y2 - y1)

whats the other formula in graphs?