Maths, Addmaths and Statistics: Post your doubts here!

[Ifarts]

yes.

R u speakin of O level ig?

 

[***amd***]

R u speakin of O level ig?

i m talking about gce, dont know about igcse though.

 

[***amd***]

Don't tell me :O
Can you explain it pleaseeeee

do you have D4 book?

 

[princess Anu]

yess

 

[***amd***]

yess

open pg 74 of its addendum, its all written there.

 

[DaniyalK]

Need help with part b.

 

[Awesome12]

Need help with part b.

 

[Ameena Eesa]

can't we cancel this down? what are the rules for cancellation?.............




add pi to the last step.......

and now, the radius should be 9, as in the ms. can u show me pls how we get it?......

 

[Ameena Eesa]

View attachment 41081

View attachment 41082 can't we cancel this down? what are the rules for cancellation?.............


View attachment 41085

add pi to the last step.......

and now, the radius should be 9, as in the ms. can u show me pls how we get it?......

help with these 3 questions plz.........

 

[DaniyalK]

1) 1200/(4050 * 100 * 100 * 100)
2) You can't because they're being subtracted.
3) 243 pi = 2*pi*r^2 + pi*r^2
243 pi = r^2(2pi + pi)
243 pi/ 3 pi = r^2
81 = r^2
9 = r

 

[Ameena Eesa]

1) 1200/(4050 * 100 * 100 * 100)
2) You can't because they're being subtracted.
3) 243 pi = 2*pi*r^2 + pi*r^2
243 pi = r^2(2pi + pi)
243 pi/ 3 pi = r^2
81 = r^2
9 = r

but the first ans is 150..........

 

[Ameena Eesa]

1) 1200/(4050 * 100 * 100 * 100)
2) You can't because they're being subtracted.
3) 243 pi = 2*pi*r^2 + pi*r^2
243 pi = r^2(2pi + pi)
243 pi/ 3 pi = r^2
81 = r^2
9 = r

for second ans, 2t and t cant be reduced?

 

[DaniyalK]

My bad, you have to take cube root of the answer (similar figures). And you can only cancel if it is 2t * 5/t* 1.

 

[Ameena Eesa]

1) 1200/(4050 * 100 * 100 * 100)
2) You can't because they're being subtracted.
3) 243 pi = 2*pi*r^2 + pi*r^2
243 pi = r^2(2pi + pi)
243 pi/ 3 pi = r^2
81 = r^2
9 = r

in third one, you divided the 4*pi*r^2 by 2 right?
so you got 2*pi*r^2......... so you only divided the 4 by two..... why not pi and r?........

 

[DaniyalK]

Think of it like this, the 4 gets cancelled with 2. It's gone then, you can't divide pi and r by 2 after that.

 

[Ameena Eesa]

My bad, you have to take cube root of the answer (similar figures). And you can only cancel if it is 2t * 5/t* 1.

can u show the steps for the cube root thingy....? cant get it

 

[DaniyalK]

Just use your calculator... cube root of 1/3375000. You get 1/150.

 

[kirann]

can anybody teach me time calculations... im quite bad at it

 

[DaniyalK]

Time questions usually just require counting and some conversion.

 

[sameersuleman]

KIRAN post a question and tell us what problems you face