Question

Use the given graph of
f(x) = x^(.5) to find a number δ such that
if |x − 4| < δ then (x^(.5) − 2) < 0.4.

Answer 1

is this that epsilon delta definition of limits?

Answer 2

http://www.khanacademy.org/math/calculus/v/epsilon-delta-limit-definition-1

Answer 3

yes it is

Answer 4

Hope that vid is of some help

Answer 5

\[
1.6^2=2.56\\
2.4^2=5.76\\
4-2.56=1.44\\
5.76-4=1.76\\
\delta=1.44
\]

Answer 6

@Anachronism did you understand it?

Answer 7

I understand why \[\epsilon ^{2} = δ \] and why you would substitute the two δs into |x − 4| < δ, but how would you decide between 1.44 and 1.76?