Asymptotes Discontinuity
1. Find the vertical and horizontal asymptotes of the curve defined by $$xy - 5x - 2y + 3 = 0.$$
Step 1: Rearrange the equation to express $y$ in terms of $x$.
$$xy - 5x - 2y + 3 = 0 \\ xy - 2y = 5x - 3 \\ y(x - 2) = 5x - 3 \\ y = \frac{5x - 3}{x - 2}$$
Step 2: Determine vertical asymptotes by finding values of $x$ that make the denominator zero.
$$x - 2 = 0 \implies x = 2$$
So, there is a vertical asymptote at $x = 2$.
Step 3: Determine horizontal asymptotes by analyzing the behavior of $y$ as $x \to \pm \infty$.
$$\lim_{x \to \pm \infty} y = \lim_{x \to \pm \infty} \frac{5x - 3}{x - 2} = \lim_{x \to \pm \infty} \frac{5 - \frac{3}{x}}{1 - \frac{2}{x}} = \frac{5 - 0}{1 - 0} = 5$$
So, the horizontal asymptote is $y = 5$.
2. For the piecewise function
$$f(x) = \begin{cases} x - 1 & x < 1 \\ 1 & x = 1 \\ 1 - x & x > 1 \end{cases}$$
Step 1: Check for continuity at $x = 1$.
Step 2: Find the left-hand limit as $x$ approaches 1:
$$\lim_{x \to 1^-} (x - 1) = 1 - 1 = 0$$
Step 3: Find the right-hand limit as $x$ approaches 1:
$$\lim_{x \to 1^+} (1 - x) = 1 - 1 = 0$$
Step 4: The function value at $x = 1$ is $f(1) = 1$.
Step 5: Since the left and right limits are equal (both 0), but $f(1) = 1 \neq 0$, the function is discontinuous at $x = 1$.
This is a removable discontinuity because the limits from both sides are equal.
Step 6: To redefine the function and remove the discontinuity, set
$$f(1) = 0$$
This makes the function continuous.