If we write x*x as x+...+x (x times), then we will see;
| x*x | = | x+...+x |
| Deriving both sides; | ||
| 2x | = | 1+...+1 |
| Summing the right hand side back; | ||
| 2x | = | x |
| This is true for all x, in particular for x=1 | ||
| 2 | = | 1 |
This causes somewhat of discomfort in mathematicians' hearts. Could you relieve them by pointing out what's wrong? Hint: x is not 0. We did not limit it at any point.