Exercise 1: Derivative of ln(x) at x=5 — Possible Solution
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STEP 1: APPLY THIS CHAPTER'S OWN DERIVATIVE TABLE
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d/dx[ln(x)] = 1/x

At x=5: 1/5 = 0.2

STEP 2: VERIFY NUMERICALLY (CENTRAL DIFFERENCE, h=1e-6)
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central_diff(ln, 5, 1e-6) = 0.20000000000575113

This matches 0.2 to within the expected tiny floating-point
precision error (differing only in the 11th decimal place).

RESULT
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ln'(5) = 0.2, confirmed both by the derivative rule and by
numerical differentiation.

WHY THIS WORKS AS AN ANSWER
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The derivative rule is applied directly using this chapter's own
stated table entry, and the numerical check uses the specific
central-difference method and step size this chapter established as
the more accurate choice, rather than an arbitrary numerical method.