Skip to content
CalcGospel 微積分福音
返回

108 政大微積分 第 12 題

考題 / 轉學考微積分 / 政大 / 微積分

108學年度 · 108微積分 · 第 12 題

題目

Problem

Suppose that f(x)=2−x+x2+sin⁡(x2)f(x)=2-x+x^2+\sin(x^2) for x∈(−∞,∞)x\in(-\infty,\infty) and gg is a function defined on (−∞,∞)(-\infty,\infty) such that g(0)=4g(0)=4 and g′(0)=2g'(0)=2. Let h(x)=g(x)/f(x)h(x)=g(x)/f(x) for x∈(−∞,∞)x\in(-\infty,\infty). Which of the following statements is true?

(a) −∞<h′(0)≤0-\infty<h'(0)\le 0.

(b) 0<h′(0)≤10<h'(0)\le 1.

(c) 1<h′(0)<∞1<h'(0)<\infty.

(d) h′(0)h'(0) exists but the value of h′(0)h'(0) cannot be determined based on the given information.

(e) The existence of h′(0)h'(0) cannot be guaranteed based on the given information.

解答

解法一

思路

展開
  • 以商數法則代入 f(0),f′(0),g(0),g′(0)f(0),f'(0),g(0),g'(0)。

答題過程

展開 f(0)=2,f′(0)=−1.f(0)=2,\qquad f'(0)=-1.

因此

h′(0)=g′(0)f(0)−g(0)f′(0)f(0)2=2⋅2−4(−1)4=2.h'(0)=\frac{g'(0)f(0)-g(0)f'(0)}{f(0)^2} =\frac{2\cdot2-4(-1)}4=2.

答案為 (c)\boxed{\text{(c)}}。