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View Full Version : What's the derivative of ... {sqrt (2x)} ?


urbantrained
Oct30-03, 12:15 PM
I'm told that you don't need the product rule, or chain rule, or quotient rule to work it out. Can anyone show the workings as well please...???

HallsofIvy
Oct30-03, 12:33 PM
I don't see anyway to find the derivative of √(2x) without using the chain rule (because of the "2", not the "√").

Write f(x)= (2x)1/2 and use the "power" rule:

f'(x)= (1/2)(2x)1/2-1(2x)'
= (1/2)(2x)-1/2(2)
= 1/√(2x)

Hurkyl
Oct30-03, 05:03 PM
√(2x) = √2 √x

You can take it from here using the power rule and the scalar multiple rule.

chroot
Oct30-03, 06:09 PM
I love when you to Alfred E. Newmans fight it out.

- Warren

Hurkyl
Oct30-03, 06:16 PM
You must be mad! [6)]

HallsofIvy
Oct31-03, 05:53 PM
Hurkyl
(2x) = 2 x

You can take it from here using the power rule and the scalar multiple rule.

Oh, well, if want to do it the EASY way!