Mathematics

Mathematics

Problem

The table gives values of the derivatives of a differentiable function ff at x=2x=2. $\begin{aligned} f(2)&=3, & f'(2)&=-1, & f''(2)&=4, & f^{(3)}(2)&=0, & f^{(4)}(2)&=-8. \end{aligned}$ Using the fourth-degree Taylor polynomial for ff centered at x=2x=2, which of the following is the best approximation of f(1.9)f(1.9)? a) 3.1183.118 b) 3.1203.120 c) 3.1003.100 d) 3.1403.140
Intuitive explanation

The key is building a Taylor polynomial: it's a polynomial centered at x=2x=2 that matches ff and all its derivatives at that point. Each derivative term tells you how much the function curves or twists near x=2x=2, and you weight each by powers of the distance (x−2)(x-2). Plug in x=1.9x=1.9 to get your approximation.

Intuitive explanation

The key is building a Taylor polynomial: it's a polynomial centered at x=2x=2 that matches ff and all its derivatives at that point. Each derivative term tells you how much the function curves or twists near x=2x=2, and you weight each by powers of the distance (x−2)(x-2). Plug in x=1.9x=1.9 to get your approximation.

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