Additional Math Help HERE ONLY...!

[vanibharutham]

dont see those questions coming for additional maths :S

have no idea how to solve them

[Padapop]

[astarmathsandphysics]

Closing speed is68-8 equals 60 so t equals d/v=2.5

[astarmathsandphysics]

Q. A train 150m long is running with a speed of 68mph. In whate time will it pass a man who is running at 8mph in the same direction which the train is going.

Q. A and B undertake to do a peice of work for $600. A alone can do it in 6 days while B alone can do it in 8 days. With the help of C
     they finish it in 3 days. Find the share of each??
hope u help..

man a does $100 of work a day so in 3 days earns $300
man b does $75 dollars of work a day so earns $225

Mean c earns $600 -$225-$300=$75

ans is 300:225:75 or 4:3:1

[vanibharutham]

Closing speed is68-8 equals 60 so t equals d/v=2.5

how can u be sure that they start from the same position?

isnt this relative velocity?

Surely if The train starts off at lets say (10i + 20j) and has a velocity of 68m/s

Its position would be (10i + 20j) + 68*t


Isnt the whole thing dependent on position?

i dont know?  could you explain

[astarmathsandphysics]

They start 150 apart and mud in same direction. The one behind catches up at a seed of 60 so t=150/60

[lil^$tar]

can any1 help me with relative velocity...i dont understand it

[ramezamgad]

it simply means the velocity of 1 particle relative to another 1
there are only 2 probabilities
both are moving in the same direction so their velocities are subtracted
they are moving towards each other so their velocities are added

waiting for ur reply lil^$tar

[astarmathsandphysics]

The relative velocity is the rate at which the distance is increasing or decreasing

[Ghost Of Highbury]

hey got it...tks astar..
 

@astarmathandphysics
do u have the timetable for igcse november 2009 final..

if so can u plz upload it here.,.
or send it to eddie_adi619@hotmail.com
thanks in advance

[sweetsh]

It is not published, too early, when iit's published  it appears on CIE's website.

[Anonymous]

hey, does anyone have the Oct/Nov 08 Examiner's report?

[Ghost Of Highbury]

but the cie website says..it has been uploaded in the cie direct which requires login

i got hold of the provisional one..but no final??

[lil^$tar]

it simply means the velocity of 1 particle relative to another 1
there are only 2 probabilities
both are moving in the same direction so their velocities are subtracted
they are moving towards each other so their velocities are added

waiting for ur reply lil^$tar

ok thanx can u giv me a question on it so dat i cud see how gud i understand it

[vanibharutham]

Hi,

i was doing the following question:

The function f(x) = [ (e^x + 1) / 4 ] for the domain x ? 0

i) Obtain an expression for f^-1
ii) State the domain and range for f^-1

The first part was easy...
i got the answer, and when i checked it with the mark scheme i got the right answer, which was:
ln(4x-1)

The second part of my answer didn't match the mark scheme, and i dont seem to understand the why.

The domain, according to me should be:

x > 1/4

The range should be:

f^-1(x) > -3.2188

However, the mark scheme says that the answers are:

DOMAIN: x > 1/2
RANGE: f^-1(x) > 0

could some one please explain my mistake?