a wee bit stuck
Given f(x) = 5 + 7x – x^4, find f ' (x).
Use your result to find f ' (2)
im not sure what to do at all.
there is a rule you must follow:
$\displaystyle \frac d{dx} x^n = nx^{n - 1}$
$\displaystyle \frac d{dx}$ means the derivative with respect to $\displaystyle x$
example:
$\displaystyle f(x) = x^3 + 2x^2 + 3x + 1$
$\displaystyle \Rightarrow f'(x) = 3x^2 + 4x + 3$
(did you see how the rule was applied?)
just plug in x = 2 once you have found $\displaystyle f ' (x)Use your result to find f ' (2)
im not sure what to do at all.
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can you finish?