## Do I know my own name?

- Did you know that (a + b)2 = a2 + 2ab + b2?
- Do I know my own name? It is called the first law of squares.
- Exactly! When a = 11 and b = 7 the right side equals 112 + 2*11*7 + 72.
- You mean 324?
- Is 324 a square number?
- Of course! It is 182. 11 + 7 = 18.
- I was wondering about something.
- Me too! May be we were wondering about the same! Wouldn’t that be wonderful?
- Is  a2 + 3ab + b2 ever a square number?
- You changed the 2 for a 3.
- I know I did.
- Then it obviously can’t be a square number! I know my own name!
- Was it the same you were wondering about?
- Not exactly.
- What were you wondering about?
- I rather not say.
- Come on! Don’t be shy!
- Do you think it will rain?

Problem source: The Dude Minds…

### 5 Responses to “Do I know my own name?”

1. Chris Sears Says:

Um… I get $11^2 + 2\cdot 11 \cdot 7 + 7^2 = 324$. Am I missing something?

2. Chris Sears Says:

Oops! I guess LaTeX doesn’t work on this site. I thought it worked on all WordPress sites.

3. Jan Nordgreen Says:

Now LaTex works. I just added a plugin called WP Latex. Note: LaTex does not work in the comment preview, but it does show in the comment when it is submitted.

The plugin converts inline latex code into PNG images that are displayed in your blog posts and comments. Use either [xxxlatex]e^{\i \pi} + 1 = 0[/latex] or $xxxlatex e^{\i \pi} + 1 = 0$ syntax.

Where xxxlatex should be replaced by ‘latex’ without the quote.

$e^{\i \pi} + 1 = 0$

4. Jan Nordgreen Says:

Now to the question: I wrote that $18^2$ is 247. I am afraid I can’t find the calculator that gave me that strange answer. The error has now been corrected in the post.

5. Mike Anderson Says:

FOCUS folks!

Let a = -11 and b = 17. Then $(-11+17)^2 - 11 = 36 - 11 = 25$, a square. This certainly must generalize…

How to use LaTeX in a comment.