Math Is Fun Forum Discussion about math, puzzles, games and fun Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °
Group Theory (Page 1) Exercises Math Is Fun Forum To be used with Introduction to Groups 1 Show that the set {0} with addition is a group 2 Show that the set {0} with multiplication is a group 3 Show that the set {1} with addition is not a group 4 Show that the set {1} with multiplication is a group 5 Show that the set {-1, 1} is a group under multiplication, but not addition 6 Name the multiplicative inverse for -1 in the group
Sokoban (Page 1) Introductions Math Is Fun Forum In the west, it might be better known as "pushbox" or something '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' I'm not crazy, my mother had me tested
Factorising harder quadratics (Page 1) Help Me ! Math Is Fun Forum Here's what I do: 6 and 10 both have more than two factors so there are several alteratives to try 6 10 6 5 3 10 3 5 1 1 1 2 2 1 2 2 By trial I found that 3 times 5 - 2 times 2 gives 11 (3x ) (2x ) The 3x must multiply the 5 so (3x 2) (2x 5) I want + 11 so that fixes the signs (3x -2) (2x + 5) If you want to check first if an integer solution is lurking there you can check B^2 - 4AC to see if