Let Throughout

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

Problem

Let g(x)=∣x2−4∣+2x,x∈R.g(x)=|x^{2}-4|+2x, \qquad x\in\mathbb{R}. Throughout, show algebraic work leading to all conclusions. (a) Express gg as a piecewise–defined function without absolute value bars. (b) For each piece, compute g′(x)g'(x). (c) Solve g′(x)=0g'(x)=0 on each open interval where gg is differentiable. List all real solutions. (d) Identify every point at which g′(x)g'(x) is not defined but gg is defined. Explain why the derivative fails to exist at each such point. (e) Combine your results from parts (c) and (d) to state all critical points of gg on R\mathbb{R}. No classification of extrema is required.

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