- #1
Jhenrique
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Homework Statement
Compute: [tex]\lim_{x \to 0} = \frac{\cos(x)}{x}[/tex] [tex]\lim_{x \to 0} = \frac{\cosh(x)}{x}[/tex] [tex]\lim_{x \to 0} = \frac{\sec(x)}{x}[/tex] [tex]\lim_{x \to 0} = \frac{sech(x)}{x}[/tex]
You can't apply L'Hopital's rule unless you have an indeterminate form. What is ##\lim_{x \rightarrow 0} \cos(x)##?Jhenrique said:The Attempt at a Solution
[tex]\lim_{x \to 0} = \frac{\cos(x)}{x} = \lim_{x \to 0} \frac{ \frac{d}{dx}\cos(x)}{\frac{d}{dx}x} = \lim_{x \to 0} \frac{- \sin(x)}{1} = 0[/tex]
Is 1jbunniii said:You can't apply L'Hopital's rule unless you have an indeterminate form. What is ##\lim_{x \rightarrow 0} \cos(x)##?
Mark44 said:Minor point, but you're showing all your limits incorrectly.
This --
$$\lim_{x \to 0} = \frac{\cos(x)}{x}$$
-- should be written without the = between "lim" and the function you're taking the limit of.
The limit of cos(x)/x as x approaches 0 is equal to 1.
The limit of sec(x)/x as x approaches 0 is equal to 0.
This is because the limit of cos(x) is equal to 1 and the limit of x is equal to 0. Therefore, the limit of cos(x)/x is equal to the limit of cos(x) divided by the limit of x, which is equal to 1.
This is because as x approaches 0, the value of sec(x) approaches infinity. Therefore, the limit of sec(x)/x is equal to the limit of infinity divided by 0, which is equal to 0.
Yes, the limit of cos(x)/x and sec(x)/x can be calculated at any value of x. However, the value of the limit may differ depending on the value of x and may not always be equal to 1 or 0.