# finding limit of trig

• February 3rd 2010, 11:09 AM
maybnxtseasn
finding limit of trig
any idea on how to solve this i have no idea where to start on these type of functions :(?

limit of (4x/tanx)
x> (pie/4)

x is approaching pie over 4
• February 3rd 2010, 12:07 PM
pickslides
What do you think of this?

$\lim_{x\to \frac{\pi}{4}}\frac{4x}{\tan x}$

$= \frac{4\frac{\pi}{4}}{\tan \frac{\pi}{4}}$

$
= \frac{\pi}{1} = \pi
$
• February 3rd 2010, 12:09 PM
Quote:

Originally Posted by maybnxtseasn
any idea on how to solve this i have no idea where to start on these type of functions :(?

limit of (4x/tanx)
x> (pie/4)

x is approaching pie over 4

It's in determinant form isn't it? You don't need to do any simplification. You can use direct substitution.

$\tan\left(\frac{\pi}{4}\right)=1$

$4\left(\frac{\pi}{4}\right)=\pi$

So $\lim_{x->\frac{\pi}{4}}\frac{4x}{\tan(x)}=\pi$