# Evaluating limits

• September 22nd 2008, 04:50 AM
Cyberman86
Evaluating limits
(Punch) I got stuck on this two, they don't look that bad but they are using Sin and i don't know exactly what to do.

lim (sin (3x) ) / over X
x->0

-------------------------------------------------------------

lim -2 / over sin (x)
x->0

as x approaches zero from the right
• September 22nd 2008, 04:55 AM
mr fantastic
Quote:

Originally Posted by Cyberman86
(Punch) I got stuck on this two, they don't look that bad but they are using Sin and i don't know exactly what to do.

lim (sin (3x) ) / over X
x->0

[snip]

$= 3 \lim_{x \rightarrow 0}\frac{\sin (3x)}{3x}$.

You know $\lim_{t \rightarrow 0} \frac{\sin (t)}{t} = 1$, right?
• September 22nd 2008, 04:58 AM
mr fantastic
Quote:

Originally Posted by Cyberman86
[snip]
lim -2 / over sin (x)
x->0

as x approaches zero from the right

This is very sloppy but makes the point: $\frac{-2}{0^+} = - \infty$