The problem asks for the limit as x approaches -2 of the linear expression 3x + 7. A key fact: linear functions are continuous everywhere, so the limit as x approaches any point equals the function value at that point. We can evaluate directly by substituting x = -2 into the expression: 3(-2) + 7. Compute the product: 3 * (-2) = -6, then add 7: -6 + 7 = 1. Thus, as x gets arbitrarily close to -2, the expression 3x + 7 approaches 1, since there are no discontinuities to cause any jump or undefined behavior. This substitution method works here because the function is a simple polynomial (specifically linear), which guarantees smooth behavior at every x, including x = -2. Therefore, the limit equals the value obtained by direct substitution into the expression.

题目

数值题

Find the limit

查看解析

标准答案

Please login to view

思路分析

The problem asks for the limit as x approaches -2 of the linear expression 3x + 7. A key fact: linear functions are continuous everywhere, so the limit as......Login to view full explanation