differentiate

Y_Shun SG

x ln 2x – 0.5x with respect to x

lpx88 SG

Lemme try..if wrong paiseh..

Use product rule?

xln2x - 1/2x
=

x(2/2x) + (1)ln2x - (1/2)

=

(1) + ln2x - (1/2)

= ln2x +1/2

Y_Shun SG

:O ans correct.

but differentiate ln2x is

1/2x or

(1/2x)(d/dx 2x) ????

lpx88 SG

1/2x

ln2x is only recognised as 1 single term.

Y_Shun SG

no no...when differentiate its suppose to be

1/[2x] then you are oso supposed to differentiate the 2x, and.... maybe wait for someone to confirm

i asked another fren, his ans and mine correct...

lpx88 SG

when u differentiate ln2x the final ans will alr be 1/2x. i think no need to differentiate further..is that what ur tryin to ask?

Y_Shun SG

err...no.

can we get someone in to differentiate this qtn? LOL

unclebutcher SG

differentiate ln(ax) = 1/ax

easy

Y_Shun SG

then in what case do we need to differentiate ax again?

Y_Shun SG

what abt this: d/dx ln f( x ) = f ’ ( x ) / f ( x )

eagle SG

Rolling Eyes

ln(ax) = ln a + ln x

differentiatie ln (ax) is thus 1/x

same as

differentiate ln (ax) = 1/ax * a = 1/x

eagle SG

u sure?

angelfairy SG

2/2x = 1/x -.-

unclebutcher SG

sorry

wrong

d/dx ln(ax) = (1/ax)(a)

unclebutcher SG

x(1/x)+ln(2x) -0.5=

ln(2x) + 0.5

Y_Shun SG

assessment book ans give ln2x

but my ans is ln2x+0.5

okay...so did anyone of you worked for that assessment book publisher before? Laughing

lpx88 SG

I tink the publisher committed the same careless mistake as me.... take ln2x as 1/2x thats why Laughing

eagle SG

Trust yourself more sometimes.