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Topic: Re: Irrational Primitive
Replies: 1   Last Post: Oct 14, 2017 7:51 PM

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 magidin@math.berkeley.edu Posts: 11,749 Registered: 12/4/04
Re: Irrational Primitive
Posted: Oct 14, 2017 7:51 PM

On Tuesday, October 10, 2017 at 5:00:11 PM UTC-5, Mr : K.H wrote:
> the primitive F(x)=ln(x) of function f(x)=1/x can be otherway maybe ? The by-product of an even function is odd. But the primitive of an odd function is not an even function. then F(x) can be odd.

Actually, ln(x) is A primitive of the function f(x) = 1/x, x>0, defined only on the positive integers. This function is neither odd nor even.

A primitive of the function f(x)=1/x is F(x) = ln|x| (natural log of the absolute value of x). This function is even.

However, it is not THE primitive. There are infinitely many primitives; the functions F(x)= ln|x| + C, for any constant C, are all primitives of the function f(x) = 1/x.
--
Arturo Magidin

Date Subject Author
10/12/17 Mr : K.H
10/14/17 magidin@math.berkeley.edu