limit as x approaches 1+of (4x-1)/(x-1)

解

x \to 1 + lim (\frac{4 x - 1}{x - 1})

\infty

解答ステップ

x \to 1 + lim (\frac{4 x - 1}{x - 1})

\frac{4 x - 1}{x - 1} = (4 x - 1) \frac{1}{x - 1}

= x \to 1 + lim ((4 x - 1) \frac{1}{x - 1})

x \to a lim [f (x) \cdot g (x)] = x \to a lim f (x) \cdot x \to a lim g (x)

不定形式の場合を除く

= x \to 1 + lim (4 x - 1) \cdot x \to 1 + lim (\frac{1}{x - 1})

x \to 1 + lim (4 x - 1) = 3

x \to 1 + lim (\frac{1}{x - 1}) = \infty

= 3 \cdot \infty

無限大の特性を適用する:

c \cdot \infty = \infty

= \infty