- #1

- 10

- 0

## Homework Statement

Let [tex] L\in R [/tex] and define

[tex]

h(x) = \begin{cases} sin(1/x) & \text{ if } x \neq 0 \\ L & \text{ if } x = 0 \end{cases}

[/tex]

Prove that h is not continuous at 0

## Homework Equations

My Professor gave us the hint "Prove by contradiction, taking [tex] \epsilon = 1/2 [/tex]"

## The Attempt at a Solution

I didn't see how this hint was relevant, but it seems too easy. All I did was say since a function is continuous at a point if it is differentiable at that point, then take 0. then h(x) = L and by first principles

lim h->0 f(x +h) - f(x) / h = L/0 which does not exist, and therefore the function is not continuous.

Why would he give that hint, and the piecewise function, when it could be proven so simply? Thanks in advance.