1. Problem: Sketch the function $y = -2 \log_3 (x + 4)$ and state its domain, range, asymptotes, and intercepts.
2. Domain: The argument of the logarithm must be positive:
$$x + 4 > 0 \implies x > -4$$
So, the domain is $(-4, \infty)$.
3. Range: Since the logarithm function can take any real value and is scaled by $-2$, the range remains all real numbers:
$$\text{Range} = (-\infty, \infty)$$
4. Vertical asymptote: The logarithm has a vertical asymptote where its argument is zero:
$$x + 4 = 0 \implies x = -4$$
5. Intercepts:
- To find the $y$-intercept, set $x=0$:
$$y = -2 \log_3 (0 + 4) = -2 \log_3 4$$
- To find the $x$-intercept, set $y=0$:
$$0 = -2 \log_3 (x + 4) \implies \log_3 (x + 4) = 0$$
$$x + 4 = 3^0 = 1 \implies x = -3$$
6. Sketch description:
- The graph has a vertical asymptote at $x = -4$.
- It passes through $(-3, 0)$ (the $x$-intercept).
- It passes through $(0, -2 \log_3 4)$ (the $y$-intercept).
- The graph is reflected vertically (due to the negative sign) and stretched by a factor of 2.
Log Function Sketch 14Ab0F
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.