题目
Find the set of values of satisfying the inequality , giving your answer to significant figures.
题目中文翻译
求满足不等式 的 的取值范围,答案保留 位有效数字。
原卷通用作答要求
Answer all questions. You should use a calculator where appropriate.
You must show all necessary working clearly; no marks will be given for unsupported answers from a calculator.
Give non-exact numerical answers correct to 3 significant figures, or 1 decimal place for angles in degrees, unless a different level of accuracy is specified in the question.
请回答所有题目。适当时应使用计算器。必须清楚展示所有必要的计算过程;仅给出计算器答案而没有过程,不予评分。除非题目另有精度要求,非精确数值答案保留 3 位有效数字,以度为单位的角度保留 1 位小数。
解答
解法一
思路
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把绝对值不等式化成双边不等式。底数 ,取对数后不等号方向不变。
答题过程
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The inequality is equivalent to
so
Taking logarithms and dividing by gives
Therefore
The boundary values are and . Thus, to 3 significant figures,