One sided limit

• February 17th 2009, 11:56 AM
3389
One sided limit
Hello!

I got a problem understanding this function
g(x) = -2x²+4x, x < -1
13, x = -1
2x^3+3, -1 < x

what is the
lim g(x) ?
x-> (-1)-

I found it equals to 1, since 2(-1)^3+3 = 1.
but apparently, it is incorrect. how come?
• February 17th 2009, 12:07 PM
Plato
You are looking at the wrong side of $-1$.
$\lim _{x \to - 1^ - } \text{ means }x < - 1$