- #1
bigplanet401
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Homework Statement
Show that the function
[tex]
f(x) =\\
\begin{cases}
\frac{1}{x} &\quad 0 < x \leq 1\\
0 &\quad x = 0
\end{cases}
[/tex]
is unbounded.
Homework Equations
If f is bounded, |f(x)| <= M for all x in f's domain.
The Attempt at a Solution
I tried arguing by contradiction: suppose there is such an M. Then |f(x)| = f(x) <= M. But if f(x) < 1/M, f(x) > M. But I get stuck because that means this particular choice of bound does not work. Instead, choose N > M. But then f(x) < 1/N makes f(x) > N. There might be a bound, and I'm having trouble proving that there is not a bound.
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