51293212
For \(f(x) = \frac{1}{x} + c\), where \(c\) is any real number, determine whether there is a value of \(c\) for which the graph crosses the y-axis. Justify your answer using the domain.
Hints
- What does changing \(c\) do to the graph?
- Does a vertical translation change whether \(x = 0\) can be substituted?
- Examine the denominator.
Solution
1. The denominator cannot equal zero, so \(x = 0\) is excluded from the domain of \(\frac{1}{x}\).
2. Adding a constant \(c\) translates the graph vertically but does not change the denominator.
3. Therefore, \(f(0) = \frac{1}{0} + c\) is undefined for every real value of \(c\).
4. Since a y-intercept would require \(x = 0\), the graph can never cross the y-axis.
Answer
No. For every real value of \(c\), the domain is \(\mathbb{R} \setminus \{0\}\), so the graph has no y-intercept.
