Differentiate

(4x-1) * (4x-1)^0.5

I think im meant to use the product formula? But it doesn't work when i used it =(

Any help would be appreciated :). Ty

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- July 3rd 2008, 02:15 PMAshleyTDiffrentiation
Differentiate

(4x-1) * (4x-1)^0.5

I think im meant to use the product formula? But it doesn't work when i used it =(

Any help would be appreciated :). Ty - July 3rd 2008, 02:25 PMTKHunny
Why do you blame the Product Rule?

(4x-1) * (4x-1)^0.5

First, the easy way.

(4x-1) * (4x-1)^(1/2) = (4x-1)^(3/2)

(d/dx)[(4x-1)^(3/2)] = [(3/2)*(4x-1)^(1/2)]*4 = 6*(4x-1)^(1/2)

Now the Product Rule

(d/dx)[(4x-1) * (4x-1)^(1/2)] = (4x-1)*(1/2)*[(4x-1)^(-1/2)]*4 + [(4x-1)^(1/2)]*4

= 2*(4x-1)^(1/2) + 4*(4x-1)^(1/2) = 6*(4x-1)^(1/2)

That looks very similar to the other version. - July 3rd 2008, 02:30 PMAshleyT
I didnt mean to 'blame the product rule' :D. I mean it wasnt working when I did it so must be making a mistake :(. Or wasn;t meant to be doing it in the first place lol.

Thankyou very much :) - July 4th 2008, 09:02 AMTKHunny
...and thank you for your particulary positive attitude.