Qualification > Math
MAth DOubts
Alpha:
d/dx [ln f(x)] = f '(x)/ f(x), where f ' (x) is the derivative of f(x).
Derivatives:
(a) ln(1-2x) > -2/ (1-2x)
(b) ln(a+bx) > b/ (a+bx)
(c) ln(x^2(x-1)) >>> clear this one, power is only 2 or 2(x-1)?
I think you forgot to add the brackets, must have been ln((x^2)(x-1)).
For this one, use the properties of logarithms. ln ((x^2)(x-1)) = ln (x^2) + ln (x-1)
Differentiate by step to get the derivative.
ln (x^2) > 2x/ (x^2)
ln (x-1) > 1/(x-1)
Therefore, ln (x^2) + ln (x-1) = 2x/ (x^2) + 1/(x-1)
Simplify further if you want.
(d) ln(2x) > 2/2x
Twinkle Charms:
--- Quote from: ~Alpha on May 22, 2010, 11:13:02 am ---d/dx [ln f(x)] = f '(x)/ f(x), where f ' (x) is the derivative of f(x).
Derivatives:
(a) ln(1-2x) > -2/ (1-2x)
(b) ln(a+bx) > b/ (a+bx)
(c) ln(x^2(x-1)) >>> clear this one, power is only 2 or 2(x-1)?
I think you forgot to add the brackets, must have been ln((x^2)(x-1)).
For this one, use the properties of logarithms. ln ((x^2)(x-1)) = ln (x^2) + ln (x-1)
Differentiate by step to get the derivative.
ln (x^2) > 2x/ (x^2)
ln (x-1) > 1/(x-1)
Therefore, ln (x^2) + ln (x-1) = 2x/ (x^2) + 1/(x-1)
Simplify further if you want.
(d) ln(2x) > 2/2x
--- End quote ---
thankyou alpha, n
its x square multiplied by x-1, so for it we open the brackets n then differientiate? N how to do the diff. part?
Twinkle Charms:
--- Quote from: chemmaster on May 22, 2010, 10:50:18 am ---its probably cause of the implication of derivative. what do you mean dirivative of the ln functions. i dont think we need that for p3
--- End quote ---
yes ofc its there in p3, the main thing dude :p
CHEMMASTER6000:
oh woops haha , my mistake i didnt take derivative as differentiate. makes a load of sense now, i can explain here if the you dont understand the guy above
Twinkle Charms:
--- Quote from: chemmaster on May 22, 2010, 01:16:18 pm ---oh woops haha , my mistake i didnt take derivative as differentiate. makes a load of sense now, i can explain here if the you dont understand the guy above
--- End quote ---
nop i got her, actually i did it just wanted to confirm, cz sum1 was confusing me :|
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