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

You are not logged in.

- Topics: Active | Unanswered

**{7/3}****Member**- Registered: 2013-02-11
- Posts: 210

prove that if r is real,then log r is real.

There are 10 kinds of people in the world,people who understand binary and people who don't.

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,469

{7/3} wrote:

prove that if r is real,then log r is real.

hhmmm. That's going to be tough when r is a negative real number.

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**{7/3}****Member**- Registered: 2013-02-11
- Posts: 210

sorry forgot to say positive

There are 10 kinds of people in the world,people who understand binary and people who don't.

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,469

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**{7/3}****Member**- Registered: 2013-02-11
- Posts: 210

I want a proof that b for every positive b and n there is a real number x such that b^x=n

There are 10 kinds of people in the world,people who understand binary and people who don't.

Offline