f(x)=x*ln(x-2)

**Also sprach Zarathustra** · July 11th 2010, 06:57 AM

Find the intersection points with the axis of following function:

$f(x)=xln(x-2)$

Notice please that the roots are $0$ and $3$

BUT the function is not defined there!

What is the explanation for that?

**matheagle** · July 11th 2010, 07:09 AM

the domain is x>2, so 3 is ok.

**Also sprach Zarathustra** · July 11th 2010, 07:22 AM

Ok! I've got it...(My foolish mistake!!!)

Sorry, and thank you!

**HallsofIvy** · July 11th 2010, 07:25 AM

What makes you believe that x is a root?

(If it were f(x)= xln|x-3| then the roots would be x= 3 and x= 0.)

**Also sprach Zarathustra** · July 11th 2010, 07:43 AM

Originally Posted by HallsofIvy

What makes you believe that x is a root?

(If it were f(x)= xln|x-3|(you mean xln|x-2|?then the roots would be x= 3 and x= 0.)

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