I require help with a bit of maths

pinkacidbootson · 9 Jan 2007 at 03:14

How do i get from:

e^0.003t - e^0.002t = 0.08

to:

e^0.001t - 1 = 0.08e^-0.002t

I have a feeling it's blindingly obvious, but im just not seeing it! Over to you, OcUK

pinkacidbootson · 9 Jan 2007 at 03:51

Yes sorry i made a mistake and changed it slightly. Thanks for the help though. I think the equation i typed originally was an intermediate step.. or something. 4 hours of maths makes me tired

pinkacidbootson · 9 Jan 2007 at 04:01

All i had to do was divide by e^0.002t, durrrr

Now time for coffee! Yay!

pinkacidbootson · 9 Jan 2007 at 04:15

You know what, i may be totally wrong on that bit :confused:

but i thought that a/x^b = ax^-b ?

In fact yes that's correct, which explains how i got the RHS.

pinkacidbootson · 9 Jan 2007 at 04:43

Yes it should be but i seem to have missed out the 'e' on the RHS, spelling mistake! But the maths is sorted now.

pinkacidbootson · 10 Jan 2007 at 18:15

Please help, my brain has stopped working

I need to differentiate the following:

y = e^2/x + e^x

I know the chain, product and quotient rules, but this simple question is taking forever and getting me nowhere.

Again, i imagine the answer to be blindingly obvious. Could someone point me in the right direction please?

pinkacidbootson · 10 Jan 2007 at 18:22

Hows it cheating? Its not like im sat in exam right now, i just need to answer this to move onto the next part of the question. Its not homework either, just revision. Same as asking a tutor.. so, be my tutor

Enfield said:
Yeah, if you're a rocket scientist.

What the hell is it all about?

2 months ago i would have said the same thing

pinkacidbootson · 10 Jan 2007 at 19:15

Vixen said:
Rearrange the first term to be e^2.(x^-1), where e^2 is a constant

That's what i was missing, thanks

pinkacidbootson · 10 Jan 2007 at 23:09

Smithy said:
Core 3 A-Level maths by chance Johanson?

Yes! It fills me with joy!

pinkacidbootson · 11 Jan 2007 at 03:21

Im doing M1 and yes it does help to be doing physics as well. Although i am resitting it on Friday

Im finding C3 easier after a couple of days revision, it seems to be mostly about differentiation and trigonometric identities, with some graphical stuff.