- #1
hgandh
- 27
- 2
If we have a function ##f(x+\Delta x)## where ##\Delta x << x##, is it valid to approximate this as:
$$f(x + \Delta x) \approx f(x) + f'(x)\Delta x$$
even if ##\Delta x## is not necessarily small? If not, what is the valid expansion to first order?
$$f(x + \Delta x) \approx f(x) + f'(x)\Delta x$$
even if ##\Delta x## is not necessarily small? If not, what is the valid expansion to first order?