Thread: Quick question about a symbol

What does this symbol mean in mathematics?

Ö

I've been searching but cannot find a definition for it yet.

I was trying to answer this question:

Using exactly two 2s and any of the standard mathematical symbols, write down an expression whose value is five.

Solution:

Ö.2-2, which shows that two twos can make five!

Is there some trick I'm not seeing?

Originally Posted by aquajam

What does this symbol mean in mathematics?
Ö

This is a odd question. All I see is: .
I have never seen that use in a standard way.
Your text material should define its use.

A really really old use of is the second derivative of .

Originally Posted by Plato

This is a odd question. All I see is: .

That's how it appears in the book. It's a math puzzle book rather than a textbook so it does not elaborate.

An odd typo perhaps? Any ideas how you would solve the question anyway?

Originally Posted by aquajam

What does this symbol mean in mathematics?

Ö

I think it's a typo: someone was trying to produce a square root symbol on their keyboard, and it came out as a capital O umlaut. Also, the –2 should be an exponent.

In fact, .

Lol, what a funny mistake