limit as x approaches infinity of (3x+5)/(6x-8)

解

x \to \infty lim (\frac{3 x + 5}{6 x - 8})

\frac{1}{2}

十進法表記

0.5

解答ステップ

x \to \infty lim (\frac{3 x + 5}{6 x - 8})

最高の分母べき乗で割る:

\frac{3 + \frac{5}{x}}{6 - \frac{8}{x}}

= x \to \infty lim (\frac{3 + \frac{5}{x}}{6 - \frac{8}{x}})

x \to a lim [\frac{f ( x )}{g ( x )}] = \frac{lim _{x \to a} f ( x )}{lim _{x \to a} g ( x )}, x \to a lim g (x) \neq = 0

不定形式の場合を除く

= \frac{lim _{x \to \infty} ( 3 + \frac{5}{x} )}{lim _{x \to \infty} ( 6 - \frac{8}{x} )}

x \to \infty lim (3 + \frac{5}{x}) = 3

x \to \infty lim (6 - \frac{8}{x}) = 6

= \frac{3}{6}

共通因数を約分する:

3

= \frac{1}{2}