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Derivatives as Functions
2. Intro to Derivatives / Derivatives as Functions / Problem 3
Problem 3

The following formulas for f(a)f_{-}^{\(\prime\)}\(\left\)(a\(\right\)) and f+(a)f_{+}^{\(\prime\)}\(\left\)(a\(\right\)) represent the left- and right-sided derivatives of a function at a point aa, respectively:
f(a)=limh0f(a+h)f(a)hf_{-}^{\(\prime\)}\(\left\)(a\(\right\))={\(\displaystyle\]\lim\)_{h\(\to\)0^{-}}{\(\frac{f(a+h)-f(a)}{h}\)}}, f+(a)=limh0+f(a+h)f(a)hf_{+}^{\(\prime\)}\(\left\)(a\(\right\))={\(\displaystyle\]\lim\)_{h\(\to\)0^{+}}{\(\frac{f(a+h)-f(a)}{h}\)}}
Consider f(x)={6x2   if x23x4   if x>2f\(\left\)(x\(\right\))=\(\begin{cases}\)6-x^2~~~\(\text{if}\)~x\(\leq{2}\)\\ 3x-4~~~\(\text{if}\)~x\(\gt{2}\]\end{cases}\). Find f(a)f_{-}^{\(\prime\)}\(\left\)(a\(\right\)) and f+(a)f_{+}^{\(\prime\)}\(\left\)(a\(\right\)) at a=2a=2.