We are given the limit of a rational function as $x$ approaches infinity: $$ \lim_{x \to \infty} \frac{8x^2 - x + 1}{ax^2 + 8} = 1 $$ We need to find the value of $a$.
2025/5/18
1. Problem Description
We are given the limit of a rational function as approaches infinity:
\lim_{x \to \infty} \frac{8x^2 - x + 1}{ax^2 + 8} = 1
We need to find the value of .
2. Solution Steps
To find the limit of a rational function as approaches infinity, we can divide both the numerator and the denominator by the highest power of that appears in the denominator. In this case, the highest power is .
\lim_{x \to \infty} \frac{8x^2 - x + 1}{ax^2 + 8} = \lim_{x \to \infty} \frac{\frac{8x^2}{x^2} - \frac{x}{x^2} + \frac{1}{x^2}}{\frac{ax^2}{x^2} + \frac{8}{x^2}}
= \lim_{x \to \infty} \frac{8 - \frac{1}{x} + \frac{1}{x^2}}{a + \frac{8}{x^2}}
As , the terms and approach
0. Therefore,
\lim_{x \to \infty} \frac{8 - \frac{1}{x} + \frac{1}{x^2}}{a + \frac{8}{x^2}} = \frac{8 - 0 + 0}{a + 0} = \frac{8}{a}
We are given that the limit is equal to 1:
\frac{8}{a} = 1
Multiplying both sides by , we get:
8 = a
Thus, .