Basic question - derivatives and the limit process

[landshark]

Hello ,

I have a basic question about using the limit process to calculate a derivative.
Can anyone walk me through the process of deriving the limit of f(x) = 2x^2-5x+3?
My textbook's answer key for this question indicates that f'(x) is 4x-5 but I keep getting the wrong answer as i work through the calculation.

Thank you for any help you can provide!

 

[Ishuda]

Hello ,

I have a basic question about using the limit process to calculate a derivative.
Can anyone walk me through the process of deriving the limit of f(x) = 2x^2-5x+3?
My textbook's answer key for this question indicates that f'(x) is 4x-5 but I keep getting the wrong answer as i work through the calculation.

Thank you for any help you can provide!

The limit process is defined as the equivalent of
\(\displaystyle f'(x) = \lim_{\Delta x \to 0} \frac{f(x+\Delta x) - f(x)}{\Delta x}\)
Expanding that out for your particular f(x) would be
\(\displaystyle f'(x) = \lim_{\Delta x \to 0} \frac{2 (x+\Delta x)^2 - 5 (x+\Delta x) + 3 - (2 x^2 - 5 x + 3)}{\Delta x}\)

If you would show your work, we could possibly find out where you made your mistake(s).

 

[stapel]

Can anyone walk me through the process of deriving the limit of f(x) = 2x^2-5x+3?

You already have loads of step-by-step examples which have "walked you through the process", such as in your textbook, your class notes, and any online lessons you've studied. So doing one more exercise isn't likely to fix the problem.

I keep getting the wrong answer as i work through the calculation.

Please reply showing all of your work and reasoning, so we can try to find there things are going sideways. Thank you!