YAHT: Math Question

AgaBoogaBoo

Lifer
Feb 16, 2003
26,108
5
81
log z = sqrrt(log z)

sqrrt = square root of

I understand that the right side can be written as log z ^ (1/2), but I don't know what to do from there. Bases are equal at that point, so their powers should be as well, but log z doesn't have an indicated power.
 

Sukhoi

Elite Member
Dec 5, 1999
15,341
102
106
Aren't z=0, z=1 the answers? You get log z = (log z)^(1/2). Then raise each side as a power of 10 to get z = z^(1/2). Aren't the answers to that 0,1?
 

RaynorWolfcastle

Diamond Member
Feb 8, 2001
8,968
16
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substitute w = sqrt(log(z)), then solve for w. Then solve for z using your 2 solutions for w (since your eqn in terms of w qill be a quadratic)
 

eLiu

Diamond Member
Jun 4, 2001
6,407
1
0
Originally posted by: Sukhoi
Aren't z=0, z=1 the answers? You get log z = (log z)^(1/2). Then raise each side as a power of 10 to get z = z^(1/2). Aren't the answers to that 0,1?

Uhm...almost. Since you upped the powers, you need to do the same to your solution: 10^0 and 10^1 (1 and 10) are the answers here.
 

Crypticburn

Senior member
Jul 22, 2000
363
0
0
Originally posted by: Sukhoi
Aren't z=0, z=1 the answers? You get log z = (log z)^(1/2). Then raise each side as a power of 10 to get z = z^(1/2). Aren't the answers to that 0,1?

When you raise each side to the logarithmic base you get:

10^log(z) = 10^sqrt(log(z))
z = 10^sqrt(log(z))

The right hand side of the equation does not simplify to what you suggest.

sqrt(log(z)) != log(sqrt(z)) ==> 10^sqrt(log(z)) != sqrt(z)
1/2 * log(z) = log(sqrt(z)) ==> 10^(1/2 * log(z)) == sqrt(z)

RaynorWolfcastle suggested the correct method, substitution.

Crypticburn

 

Muzzan

Member
Apr 15, 2003
169
0
0
Originally posted by: Sukhoi
Aren't z=0, z=1 the answers? You get log z = (log z)^(1/2). Then raise each side as a power of 10 to get z = z^(1/2). Aren't the answers to that 0,1?

log(0) isn't defined, so z = 0 is not a solution.