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**

**limpfisch****Member**- Registered: 2012-05-08
- Posts: 11

let a,b be members of a group (G,*). Show that if (a*b) inverse = (a inverse)*(b inverse) then a*b = b*a

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 7,268

hi limpfisch

For simplification I'll leave out the * (say, multiply), use I for the identity and -1 for an inverse

multiply both sides by ab

Now multiply both sides by ba

Bob

Children are not defined by school ...........The Fonz

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

Offline

Pages: **1**