A function is defined analytically by f(x)= cases |x-2|, & x 2, (x-2)^2, & x>2

MATHEMATICS · Multi-part · A Level · Mathematics · Differentiation · Differentiation

Problem

A function ff is defined analytically by f(x)={∣x−2∣,x≤2,(x−2)2,x>2.f(x)=\begin{cases} |x-2|, & x\le 2,\\ (x-2)^2, & x>2. \end{cases} Answer the following questions about the behavior of ff at x=2x=2. (1) Part 1: (a) Calculate lim⁡x→2−f(x)\lim_{x\to2^-}f(x) and lim⁡x→2+f(x)\lim_{x\to2^+}f(x). Determine whether ff is continuous at x=2x=2, and justify your conclusion. (2) Part 2: (b) Compute lim⁡h→0−f(2+h)−f(2)h\lim_{h\to0^-}\frac{f(2+h)-f(2)}{h} and lim⁡h→0+f(2+h)−f(2)h\lim_{h\to0^+}\frac{f(2+h)-f(2)}{h}. Show all algebraic steps. (3) Part 3: (c) Using the results from part (b), determine whether ff is differentiable at x=2x=2. If the derivative fails to exist, state whether the point is a corner or a cusp and provide a brief justification based on the one-sided derivatives.

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