| f(x+h)−f(x) | ||
limh→0 | = | |
| h |
| √x+h−√x | ||
limh→0 | = | |
| h |
| x+h−x | ||
limh→0 | = | |
| h(√x+h+√x) |
| h | ||
limh→0 | = | |
| h(√x+h+√x) |
| 1 | 1 | |||
limh→0 | = | |||
| √x+h+√x | 2√x |
| √x+h − √x | ||
limh→0 | ... mnożymy licznik i mianownik przez sprzężenie ... | |
| h |
| x + h − x | 1 | 1 | 1 | |||||
= lim | = | = | = | |||||
| h*(√x+h + √x) | √x+h + √x | √x + √x | 2√x |