Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,608

Logarithm Formulas

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**ganesh****Moderator**- Registered: 2005-06-28
- Posts: 20,375

If

thenbecause

It is no good to try to stop knowledge from going forward. Ignorance is never better than knowledge - Enrico Fermi.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

Offline

**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

*Last edited by Ricky (2006-04-04 04:11:44)*

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

Offline

**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

**Logarithm of a Complex Number**

where k is an integer.

Offline

**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

(which is log(xy) = log *x* + log *y*)

*Last edited by Devanté (2006-08-05 19:10:52)*

Offline

**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

*Last edited by Devanté (2006-10-06 23:23:57)*

Offline

**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

Offline

**random_fruit****Member**- Registered: 2008-12-25
- Posts: 39

Can anyone explain Devante's post #7? He says

This does not make sense to me, and seems to me to have exactly one value of x for which it is true.

Offline

**Shekhar****Member**- Registered: 2009-04-19
- Posts: 1

Can anyone prove the following....

Given,

((2/3)^k)n = 1

Required to prove,

k is equal to log of n on base 3/2

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,908

Hi random_fruit;

It could be a quiz problem and I agree it appears to have only 1 solution in R.

*Last edited by bobbym (2009-04-19 19:44:38)*

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

Offline

**noobard****Member**- Registered: 2009-06-07
- Posts: 28

ganesh wrote:

If

then

because

hey ganesh jus a little thing

if we take A and B of the same signs

here it should be

..

and in the other ones also... the argument has to be alwys positive

Everything that has a begining has an EnD!!!

Offline

**sekhar5955****Member**- Registered: 2009-11-25
- Posts: 1

Hi Shekhar,

Here is the solution.

((2/3)^k)n = 1

⇒(2/3)^k = 1/n

⇒(2/3)^k = n-¹

Applying log on both sides.

⇒k log(2/3) = -log n

Multiplying (-) on both sides

⇒k log(2/3)-¹ = log n

⇒k log(3/2) = log n

∴ k = (log n)/(log (3/2))

⇒ k = log n base (3/2)

Shekhar wrote:

Can anyone prove the following....

Given,

((2/3)^k)n = 1

Required to prove,

k is equal to log of n on base 3/2

Offline

Pages: **1**