Maths & Physics Help

[astarmathsandphysics]

I can't use msn it conflixts with my operating system. Try yahoo or skype.

[badboy]

yo star r pipol done with physics p3 n maths p2 because  i havnt done any of maths n physics i just did the practical p5 physics but the athas i dint do

[puppy]

can sumone send me the marking schemes for maths paper 2 may/june 05 and 06?? please!!

[pixis]

have you tried www.freeexampapers.com? I will check when I get home in a couple of hours.

[astarmathsandphysics]

can sumone send me the marking schemes for maths paper 2 may/june 05 and 06?? please!!

here they are on www.freeexampapers.com

http://www.freeexampapers.com/Dndex.php?d=SUdDU0UvTWF0aHMvQ0lF&catagory=

[---<--- StUdYiNg --->---]

need help in math paper 2.hav it tmrw n m stuck in one qns.its frm may june 2008.number 10.can anyone help?? pls.....

[TravisMcDee]

need help in math paper 2.hav it tmrw n m stuck in one qns.its frm may june 2008.number 10.can anyone help?? pls.....

(Volume factor)=(scale fator)^3
therefore = sqrt(216)=vol factor
=6

[astarmathsandphysics]

Volume factor = length factor cubed
Therefore length factor = cube root of volume factor
Cube root of 216 is 6
therefore radius =3x6=18
height= 7x6=42

[qwerty]

can someone help me with functions?
lol ,thanks!

[astarmathsandphysics]

what do you want to know? Do you want questions answered?

[IGCSE Master]

Functions:

f:x = 2x - 1   and   g:x = x²-1

Find:

f-¹(x)


gf(x)

[astarmathsandphysics]

f=2x-1
Make x the subject
f+1 =2x so (f+1)/2=x
Now swap f and x
(x+1)/2=f
Now replace f by f^-1 to give (x+1)/2=f^-1

g(x)=x^2-1 so g(f)=f^2-1 but f(x)=2x-1
so g(f(x))=(2x-1)^2-1
                =(2x-1)(2x-1)-1
                =4x^2-2x-2x+1-1
                =4x^2-4x
             

[qwerty]

thanks! i think i get it. so:

f(x) = 3 x - 1

f^-1(x) would then be:

f = 3x-1
f + 1 = 3x
f+1/3 = x
swap
x+1/3 = f
f^-1 = x+1/3

is that correct??

thanks a lot!!!

[astarmathsandphysics]

should be (x+1)/3=f^-1(x)
x+1 has to be divided by 3 not just 1 divided by 3

[qwerty]

oh i get it! thanks a lot!