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**

If G is a regular graph and d, e and v denote the degree, the number of edges and the number of vertices respectively, then e = dv/2.

Prove the above statement

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'Humanity is still kept intact. It remains within.' -Alokananda

Offline

**John E. Franklin****Member**- Registered: 2005-08-29
- Posts: 3,552

since a line segment or "edge" has two ends, then yes, 1/2 is the formula. v=dots d=ends of lines on a dot. e=#ofline segs

Pretty obvious really if you draw a few. but to prove it, ask Ricky.

**igloo** **myrtilles** **fourmis**

Offline

Ricky? He's gone

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'Humanity is still kept intact. It remains within.' -Alokananda

Offline

Pages: **1**