Give step-by-step solution with explanation and final answer:
Sketch the graph of a functionf(x)which has all of the following properties.
f(x) has domain (−∞,−2)∪(−2,∞)
f(x) has range (−5,∞)
The graph of f(x) has a vertical asymptote at x=−2
limx→−∞f(x)=2
limx→∞f(x)=−5
limx→3f(x)=2
f(x) is discontinuous at x=3
f′(x)>0 on (−∞,−2)
f′(x)
Question:
Give step-by-step solution with explanation and final answer:
Sketch the graph of a functionf(x)which has all of the following properties.
f(x) has domain (−∞,−2)∪(−2,∞)
f(x) has range (−5,∞)
The graph of f(x) has a vertical asymptote at x=−2
limx→−∞f(x)=2
limx→∞f(x)=−5
limx→3f(x)=2
f(x) is discontinuous at x=3
f′(x)>0 on (−∞,−2)
f′(x)
This is AI generated Response.
Asked by: Test User 100071
Created at: 2025-04-29 11:48:06
Final Answer:
RenderedRaw Text
Did you like this answer?
Let's work through the properties **step by step**. We'll analyze and build the function \( f(x) \) that fits all the given requirements.
---
## **Step 1: Domain**
**Domain:** \( (-\infty, -2) \cup (-2, \infty) \)
- The function is undefined at \( x = -2 \).
- The function is defined everywhere else.
---
## **Step 2: Range**
**Range:** \( (-5, \infty) \)
- The function can take on any value greater than \(-5\) but **not** \(-5\).
- It never reaches \(-5\), but it can get arbitrarily close.
---
## **Step 3: Vertical Asymptote**
**Vertical Asymptote at \( x = -2 \):**
- As \( x \to -2^+ \) or \( x \to -2^- \), \( f(x) \to \pm \infty \).
---
## **Step 4: End Behavior / Horizontal Asymptotes**
**Limits at infinity:**
- \( \lim_{x \to -\infty} f(x) = 2 \)
- \( \lim_{x \to \infty} f(x) = -5 \)
So:
- As \( x \to -\infty \), function approaches \( 2 \).
- As \( x \to \infty \), function approaches \( -5 \) (but never equals).
---
## **Step 5: Limit and Discontinuity at \( x = 3 \)**
- \( \lim_{x \to 3} f(x) = 2 \)
- \( f(x) \) is **discontinuous** at \( x = 3 \)
This means either a jump, removable, or infinite discontinuity at \( x=3 \).
---
## **Step 6: Increasing/Decreasing Intervals**
- \( f'(x) > 0 \) on \( (-\infty, -2) \): Increasing to the left of \( x = -2 \)
- \( f'(x) < 0 \) on \( (-2, 3) \): Decreasing from \( x = -2 \) to \( x = 3 \)
---
## **Step 7: \( f'(4) \) Not Defined, but \( f(x) \) Continuous at 4**
- Sharp corner or cusp at \( x=4 \), but no break in the graph.
---
### **Let's Build the Function**
Let’s try to construct a function that fits these properties. We'll start with a basic rational transformation and then tweak as needed.
#### **Base function idea:**
A function with a vertical asymptote at \( x = -2 \) and horizontal asymptotes at \( y = 2 \) as \( x \to -\infty \), and \( y = -5 \) as \( x \to \infty \), and range \( (-5, \infty) \).
A rational function like:
\[
f(x) = \frac{a}{x+2} + b
\]
But this function only has one horizontal asymptote. To get **two different asymptotes** at the ends, we need a rational function where numerator and denominator have the same degree.
Let’s set:
\[
f(x) = \frac{m x + n}{x + 2}
\]
Let's find \( m, n \) so that:
- As \( x \to \infty \): \( f(x) \to m \) (since the degree is the same, divide coefficients).
- As \( x \to -\infty \): \( f(x) \to m \) (same as above).
But we want **different limits at infinity**. We need to tweak further.
Try:
\[
f(x) = \frac{A x + B}{x+2} + C
\]
But this still only allows one horizontal asymptote.
#### **Key Rational Function for Two Horizontal Asymptotes**
Let’s try this standard form:
\[
f(x) = \frac{ax + b}{cx + d}
\]
As \( x \to \infty \), \( f(x) \to \frac{a}{c} \).
As \( x \to -\infty \), \( f(x) \to \frac{a}{c} \) (since the degrees are the same).
But we want **different horizontal asymptotes**. This can be achieved by using a function like:
\[
f(x) = \frac{P(x)}{Q(x)} + R
\]
Or by shifting and stretching.
Alternatively, a function such as
\[
f(x) = \frac{N(x)}{D(x)}
\]
where the numerator and denominator are both degree 2.
Suppose:
\[
f(x) = \frac{a x^2 + b x + c}{x+2}
\]
But then as \( x \to \infty \), numerator dominates, so \( f(x) \to \infty \).
So instead, try:
\[
f(x) = \frac{a x + b}{x + 2} + d
\]
But as above, this only gives a single horizontal asymptote.
#### **Let's Try an Exponential Decay**
Alternatively, use a function with a vertical asymptote at \( x = -2 \) and horizontal asymptotes at different ends.
A function like:
\[
f(x) = -5 + \frac{A}{x+2}
\]
But as \( x \to \infty \), \( f(x) \to -5 \), as \( x \to -\infty \), \( f(x) \to -5 \).
Not enough.
#### **Solution: Use a Shifted Reciprocal Function**
Let’s look for a function that increases toward \( 2 \) as \( x \to -\infty \), and decreases toward \( -5 \) as \( x \to \infty \), and has vertical asymptote at \( x=-2 \).
Let’s set:
\[
f(x) = \frac{K}{x+2} + L
\]
Let’s find \( K \) and \( L \).
As \( x \to -\infty \), \( f(x) \approx L \)
As \( x \to \infty \), \( f(x) \approx L \)
Still both ends go to \( L \).
But if we introduce a negative sign and a shift:
\[
f(x) = a + \frac{b}{x+2}
\]
Same problem.
Let’s try a function like:
\[
f(x) = -5 + \frac{7}{1 + e^{x+2}}
\]
But as \( x \to \infty \), \( e^{x+2} \to \infty \Rightarrow f(x) \to -5 \).
As \( x \to -\infty \), \( e^{x+2} \to 0 \Rightarrow f(x) \to -5 + 7 = 2 \).
**This matches the behavior!**
- Vertical asymptote at \( x = -2 \)? Let's check the denominator at \( x=-2 \):
\[
1 + e^{-2 + 2} = 1 + e^{0} = 2 \neq 0
\]
**So this function is continuous at \( x = -2 \), not a vertical asymptote.**
#### **Try a Negative Exponent:**
\[
f(x) = -5 + 7 \cdot e^{-(x+2)}
\]
As \( x \to \infty \), \( e^{-(x+2)} \to 0 \Rightarrow f(x) \to -5 \)
As \( x \to -\infty \), \( e^{-(x+2)} \to \infty \Rightarrow f(x) \to \infty \)
So, not quite.
#### **Try Rational Function with Quadratic Denominator**
Let’s try:
\[
f(x) = \frac{A}{x + 2} + B
\]
We already tried this.
Try:
\[
f(x) = \frac{C}{x + 2} + D
\]
Let’s force the limits:
- As \( x \to -\infty \), \( f(x) \to D \)
- As \( x \to \infty \), \( f(x) \to D \)
Not sufficient.
#### **A Better Approach: Use Reciprocal with Different Numerator**
Try:
\[
f(x) = \frac{ax + b}{x+2}
\]
Find \( a, b \) so that:
- As \( x \to \infty \), \( f(x) \to a \) (since degrees are the same)
- As \( x \to -\infty \), \( f(x) \to a \)
Still both ends same.
#### **Try a Rational Function with Horizontal Asymptotes at Different Ends**
A function like
\[
f(x) = \frac{p}{1 + e^{x}}
\]
has horizontal asymptotes at \( y = p \) and \( y = 0 \).
So, we can **combine two horizontal
VIPSolutions focuses on clear, step‑by‑step explanations so you can learn quickly. Whether you need an AI‑generated walkthrough or a short hint to get unstuck, each solution is organized for fast reading and easy review later.
Search similar questions, compare approaches, and bookmark the best answers for revision. Our goal is simple: quick, reliable study help that feels natural—not noisy.