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EXAMPLE 2Using L’Hôpital’s Rule to Find a Limit

Find lim.

Solution We follow the steps for finding a limit using L’Hôpital’s Rule.

Step 1 Since \lim\limits_{x\rightarrow 0}\tan x=0 and \lim\limits_{x\rightarrow 0}( 6x) =0, the quotient \dfrac{\tan x }{6x} is an indeterminate form at 0 of the type \dfrac{0}{0}.

Step 2\dfrac{d}{\textit{dx}}\tan x=\sec ^{2}x and \dfrac{d}{\textit{dx}}\left( 6x\right) =6.

Step 3\lim\limits_{x\rightarrow 0}\dfrac{\dfrac{d}{\textit{dx}}\tan x}{\dfrac{d}{dx}\left( 6x\right) }= \lim\limits_{x\rightarrow 0}\dfrac{\sec ^{2}x}{6}=\dfrac{1}{6}.

It follows from L’Hôpital’s Rule that \lim\limits_{x\rightarrow 0}\dfrac{\tan x}{6x}=\dfrac{1}{6}.