Mathematics: Post your doubts here!

[786]

okay but how did u get that what did u divide by

 

[Lostsoul]

I do not know how to get the invariant line for shear and stretch, i mean if you look for the prependiculat height, then its parallel to both at timess, or I don't know how to find an invariant line. I seriousllyy need hellpp URGENTLYY!

 

[786]

oh okay u add then divid by 2 thanks

 

[Lostsoul]

okay but how did u get that what did u divide by

You add 170 and 160 and then divide it by 2

 

[Reem2195]

PLEASE HELP!
the very last question in the paper attached

Question 9c
It's so hard and I have to understand it because my exam is tomorrow and I'm definitely sure that sequences are coming!!
They showed up on all the recent papers...

I've also attached the mark scheme. It might make it easier to explain.

 

[Lost_Life]

GUYS GOOD LUCK AND HOPEFULLY WE ALL GET STRAIGHT A* IN OUR IGCSE
ameen ya rab..

 

[aliiiiiiiiii]

help plzzzzzzzz in http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_43.pdf
Q 7 a

 

[Lost_Life]

Guys can anyone show me how to draw stretch and shear transformation with a negative scale factor?

 

[GetSomeLife]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w11_qp_43.pdf
Question 8 part e)!

It's easy:
h inverse (x) = x
h inverse (x) = 2
x = 2

Put x=2
h(x) = 3^x
h(x) = 3^2
h(x) = 9

Could you please help me with O/N 11 variant 42 question 7) f) i) as well please??
Thanks in advance!
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_w11_qp_42.pdf

x^3 - x^2 -2x + 1 = 0
Take 1 to the other side
x^3 - x^2 - 2x = -1
take 'x' common
x(x^2 - x - 2) = -1
x^2 - x - 2 = -1/x
bring -1/x back here and take -x - 2 back there
x^2 + 1/x = x + 2
a = 1
b = 2

 

[shefali]

hey guys..can u confirm if mark scheme for sum number 2) d) iii paper october/november 2005 is wrong?

 

[GetSomeLife]

Thank you so much!
how can h inverse of x=x?? since its h^x so how can you find the inverse of something if its something to the power of x?? :/

Actually, it's what you call a FACT or so my sir told me.
You can always write h inverse (x) = x
or
h inverse (323) = x
or
h inverse ('anything') = x

For example:

h(x) = x + 2
Find:
h inverse (23)

We can write
h inverse (23) = x
Move h inverse to the other side... the inverse is removed! (I know this is something new but it's always effective)

h(x) = 23
x + 2 = 23
x = 21

Now let's see that question

h inverse(x) = 2
Move h inverse to the other side
h(2) = x
h(2) = 3^2
h(2) = 9

Hard to understand but once you do, it's awesome

 

[shefali]

Thank you so much!
how can h inverse of x=x?? since its h^x so how can you find the inverse of something if its something to the power of x?? :/

you write it as log y= x log 3
then x= log y / log3
hence (log x/ log 3)=2
which means 2*log 3
and then log inverse

 

[shefali]

Actually, it's what you call a FACT or so my sir told me.
You can always write h inverse (x) = x
or
h inverse (323) = x
or
h inverse ('anything') = x

For example:

h(x) = x + 2
Find:
h inverse (23)

We can write
h inverse (23) = x
Move h inverse to the other side... the inverse is removed! (I know this is something new but it's always effective)

h(x) = 23
x + 2 = 23
x = 21

Now let's see that question

h inverse(x) = 2
Move h inverse to the other side
h(2) = x
h(2) = 3^2
h(2) = 9

Hard to understand but once you do, it's awesome

i dont think it would work for all equations...log is a lot easier

 

[Hamzeh S]

Negative Shear And Scale ! ??? can you please explain

 

[GetSomeLife]

i dont think it would work for all equations...log is a lot easier

Actually, it would And i don't think log is there for students who take o580 Math... it's for add math students

 

[shefali]

Negative Shear And Scale ! ??? can you please explain

negative shear simply moves to the left side instead of right
Transformations:http://www.gcsemathstutor.com/transformations.php
http://www.s-cool.co.uk/gcse/maths/transformations/revise-it/transformations

 

[shefali]

Actually, it would And i don't think log is there for students who take o580 Math... it's for add math students

i dont know if its mathematically correct but ok

 

[aliiiiiiiiii]

help plzzzzzzzz in http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_43.pdf
Q 7 a

 

[GetSomeLife]

help plzzzzzzzz in http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Mathematics (0580)/0580_s10_qp_43.pdf
Q 7 a

Mode: 11 (because it has the highest frequency)
Median: 12+13/2 = 12.5
Mean = (11*35 + 12*28 + 13*22 + 14*18 + 15*14 + 16*9)/(35 + 28 + 22 + 18 + 14 + 9) = 12.8

 

[GetSomeLife]

Thank you so much I actually get it now and it feels good!

No need of thanking! Just pray! PLEASE