- #1

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Consider that ##f': x' \mapsto f'(x')## and ##f: x \mapsto f(x)##. If ##x' = x + \sigma##, with ##|\sigma| << 1##, can we say that ##f'(x') \approx f(x')##?

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- Thread starter kent davidge
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- #1

- 931

- 56

Consider that ##f': x' \mapsto f'(x')## and ##f: x \mapsto f(x)##. If ##x' = x + \sigma##, with ##|\sigma| << 1##, can we say that ##f'(x') \approx f(x')##?

- #2

fresh_42

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- #3

Mark44

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If you have two different functions, why not call them f and g? Or ##f_1## and ##f_2##? Your notation ##f'(x')## looks like we're evaluating the derivative of f at a number x'.

Consider that ##f': x' \mapsto f'(x')## and ##f: x \mapsto f(x)##. If ##x' = x + \sigma##, with ##|\sigma| << 1##, can we say that ##f'(x') \approx f(x')##?

- #4

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Yea, I agree. Coincidentally I was going to write them down as ##f## and ##g## in the opening post, but I used the more abstract notation.If you have two different functions, why not call them f and g? Or ##f_1## and ##f_2##? Your notation ##f'(x')## looks like we're evaluating the derivative of f at a number x'.

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