Little Logs confusion. (1 Viewer)

RishBonjour

Well-Known Member
Joined
Aug 14, 2011
Messages
1,261
Gender
Male
HSC
2012
had my 2u trial today.
there was a questions like:

2ln(3x^(1/2)) =...

I got my final answers as something, and a -3

Now, the -3 satisfied the RHS

but for 2ln(3x^(1/2))

It only satisfies the equation if 2 is taken to be the power in side i.e. ln((3x^(1/2))^2)

so is -3 a solution?
 

RishBonjour

Well-Known Member
Joined
Aug 14, 2011
Messages
1,261
Gender
Male
HSC
2012
Just realised I wrote the question wrong it was simply a solve for x question. (can't remember it exactly)

2ln(xroot3)=ln(something)

basic quadratics, but I got a bit stuffed about the negative answer :/ It was only valid if I raised everything in ln to the power of 2
 

D94

New Member
Joined
Oct 5, 2011
Messages
4,426
Gender
Male
HSC
N/A
No, -3 is not a solution.
 

RishBonjour

Well-Known Member
Joined
Aug 14, 2011
Messages
1,261
Gender
Male
HSC
2012
dammnnnnnnnn :(

but, why can't the 2 be raised inside?

then it would be ln(3x^2) and the equation becomes true for all x?

edit:
FUCK
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top