For the function f(x)=x|x|, show that f'(0) exists. wht is the value?

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- Aug 9th 2010, 10:12 PMalexpremSolved
For the function f(x)=x|x|, show that f'(0) exists. wht is the value?

- Aug 9th 2010, 10:25 PMpickslides

Maybe use the product rule from here? - Aug 9th 2010, 10:58 PMProve It
is not differentiable at , so what makes you think that is differentiable there?

- Aug 9th 2010, 10:58 PMAlso sprach Zarathustra
x|x| = sgn(x) * x^2

- Aug 10th 2010, 04:06 AMHallsofIvy

For f(x)= x|x|, this is .

Yes, Prove It, even though |x| is not differentiable at x= 0, x|x| is! - Aug 10th 2010, 05:23 AMeumyang
Posted by pickslides from this thread:

http://www.mathhelpforum.com/math-he...on-153220.html

Quote:

Wow this is really similar to http://www.mathhelpforum.com/math-he...on-153221.html

Are you in the same class or the same person?

http://www.mathhelpforum.com/math-he...ve-153114.html

Coincidence? (Wondering) - Aug 10th 2010, 11:34 AMilovemymath
might be someone from my class

because we are taking this over online so many of us will have problem as we are not being taught anything - Aug 10th 2010, 12:28 PMskeeter