Question
upstudy study bank question image url

(2) Find vertical and horizontal asymptotes of the following functions. Show your work. Evaluate all the necessary limits. (i) \( f(x)=\frac{2 x-1}{3 x^{2}+5 x-2} \) (ii) \( f(x)=\frac{-x^{3}+2 x^{2}}{x^{4}-4 x^{3}+4 x^{2}} \)

Ask by Chandler Turnbull. in Canada
Jan 26,2025

Real Tutor Solution

Tutor-Verified Answer

Answer

**Asymptotes:** 1. **Function (i):** - **Vertical Asymptotes:** \( x = \frac{1}{3} \) and \( x = -2 \) - **Horizontal Asymptote:** \( y = 0 \) 2. **Function (ii):** - **Vertical Asymptote:** \( x = 2 \) - **Horizontal Asymptote:** \( y = 0 \)

Solution

Let's analyze each function to find their vertical and horizontal asymptotes by evaluating the necessary limits and performing algebraic simplifications where needed. --- ### **Problem (i)** **Function:** \[ f(x) = \frac{2x - 1}{3x^2 + 5x - 2} \] #### **1. Vertical Asymptotes** Vertical asymptotes occur where the denominator is zero (since the function is undefined there) and the numerator is not zero at those points. 1. **Find the roots of the denominator:** \[ 3x^2 + 5x - 2 = 0 \] 2. **Solve the quadratic equation using the quadratic formula:** \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \] Here, \( a = 3 \), \( b = 5 \), and \( c = -2 \). 3. **Calculate the discriminant:** \[ \Delta = b^2 - 4ac = 25 + 24 = 49 \] 4. **Find the roots:** \[ x = \frac{-5 \pm \sqrt{49}}{6} = \frac{-5 \pm 7}{6} \] - \( x = \frac{2}{6} = \frac{1}{3} \) - \( x = \frac{-12}{6} = -2 \) 5. **Check the numerator at these points:** \[ \text{At } x = \frac{1}{3}: \quad 2\left(\frac{1}{3}\right) - 1 = \frac{2}{3} - 1 = -\frac{1}{3} \neq 0 \] \[ \text{At } x = -2: \quad 2(-2) - 1 = -4 - 1 = -5 \neq 0 \] Since the numerator is not zero at \( x = \frac{1}{3} \) and \( x = -2 \), these are indeed vertical asymptotes. **Vertical Asymptotes:** \[ x = \frac{1}{3} \quad \text{and} \quad x = -2 \] #### **2. Horizontal Asymptote** To determine the horizontal asymptote, compare the degrees of the numerator and the denominator. - **Degree of the numerator (2x - 1):** 1 - **Degree of the denominator (3x² + 5x - 2):** 2 Since the degree of the denominator is greater than the degree of the numerator, the horizontal asymptote is: \[ y = 0 \] --- ### **Problem (ii)** **Function:** \[ f(x) = \frac{-x^3 + 2x^2}{x^4 - 4x^3 + 4x^2} \] #### **1. Simplify the Function** First, factor both the numerator and the denominator: 1. **Factor the numerator:** \[ -x^3 + 2x^2 = -x^2(x - 2) \] 2. **Factor the denominator:** \[ x^4 - 4x^3 + 4x^2 = x^2(x^2 - 4x + 4) = x^2(x - 2)^2 \] 3. **Simplify the function by canceling common factors:** \[ f(x) = \frac{-x^2(x - 2)}{x^2(x - 2)^2} = \frac{-1}{x - 2} \] **Note:** The factors \( x^2 \) and \( (x - 2) \) in the numerator and denominator cancel out, except for one \( (x - 2) \) in the denominator. However, \( x = 0 \) causes both numerator and denominator to be zero, indicating a **removable discontinuity** (a hole) at \( x = 0 \), not a vertical asymptote. #### **2. Vertical Asymptote** After simplification, the function becomes: \[ f(x) = \frac{-1}{x - 2} \] The denominator is zero when: \[ x - 2 = 0 \quad \Rightarrow \quad x = 2 \] **Behavior near \( x = 2 \):** \[ \lim_{x \to 2^+} f(x) = \lim_{x \to 2^+} \frac{-1}{x - 2} = -\infty \] \[ \lim_{x \to 2^-} f(x) = \lim_{x \to 2^-} \frac{-1}{x - 2} = +\infty \] Since the limits approach infinity from different directions, there is a vertical asymptote at \( x = 2 \). **Vertical Asymptote:** \[ x = 2 \] #### **3. Horizontal Asymptote** Compare the degrees of the original numerator and denominator: - **Degree of the numerator (-x³ + 2x²):** 3 - **Degree of the denominator (x⁴ - 4x³ + 4x²):** 4 Since the degree of the denominator is greater than the degree of the numerator, the horizontal asymptote is: \[ y = 0 \] --- ### **Summary of Asymptotes** 1. **Function (i):** - **Vertical Asymptotes:** \( x = \frac{1}{3} \) and \( x = -2 \) - **Horizontal Asymptote:** \( y = 0 \) 2. **Function (ii):** - **Vertical Asymptote:** \( x = 2 \) - **Horizontal Asymptote:** \( y = 0 \)

Reviewed and approved by the UpStudy tutoring team

error msg
Explain
Simplify this solution

Extra Insights

To find the vertical and horizontal asymptotes of the given functions, we will evaluate limits and identify points of discontinuity. **(i) \( f(x)=\frac{2 x-1}{3 x^{2}+5 x-2} \)** 1. **Vertical Asymptotes:** Vertical asymptotes occur where the denominator is equal to zero and the numerator is not zero at those points. We need to set the denominator to zero: \[ 3x^2 + 5x - 2 = 0 \] Factoring or using the quadratic formula: \[ x = \frac{-5 \pm \sqrt{(5)^2 - 4(3)(-2)}}{2(3)} = \frac{-5 \pm \sqrt{25 + 24}}{6} = \frac{-5 \pm 7}{6} \] This yields: \[ x = \frac{1}{3} \quad \text{and} \quad x = -2 \] Thus, vertical asymptotes are at \( x = \frac{1}{3} \) and \( x = -2 \). 2. **Horizontal Asymptotes:** For rational functions, the horizontal asymptotes depend on the degrees of the polynomial in the numerator and denominator. Here, the degree of the numerator (1) is less than the degree of the denominator (2). Therefore: \[ y = 0 \quad \text{(the x-axis)} \] This means there is a horizontal asymptote at \( y = 0 \). --- **(ii) \( f(x) = \frac{-x^{3} + 2x^{2}}{x^{4} - 4x^{3} + 4x^{2}} \)** 1. **Vertical Asymptotes:** To find vertical asymptotes, we set the denominator to zero: \[ x^{4} - 4x^{3} + 4x^{2} = 0 \implies x^{2}(x^{2} - 4x + 4) = 0 \] This gives: \[ x^2 = 0 \quad \text{or} \quad (x - 2)^2 = 0 \] Thus, we have a vertical asymptote at \( x = 0 \) and a repeated root at \( x = 2 \), indicating a vertical asymptote at \( x=2 \). 2. **Horizontal Asymptotes:** The degree of the numerator (3) is less than the degree of the denominator (4). Therefore, there is a horizontal asymptote at: \[ y = 0 \] So, for this function, there is also a horizontal asymptote at \( y = 0 \). To summarize, the vertical asymptotes for the first function are at \( x = \frac{1}{3} \) and \( x = -2 \) with a horizontal asymptote at \( y = 0 \). The second function has vertical asymptotes at \( x = 0 \) and \( x = 2 \), with a horizontal asymptote at \( y = 0 \).

Try Premium now!
Try Premium and ask Thoth AI unlimited math questions now!
Maybe later Go Premium
Study can be a real struggle
Why not UpStudy it?
Select your plan below
Premium

You can enjoy

Start now
  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to Answer and Solution
  • Full Access to PDF Chat, UpStudy Chat, Browsing Chat
Basic

Totally free but limited

  • Limited Solution
Welcome to UpStudy!
Please sign in to continue the Thoth AI Chat journey
Continue with Email
Or continue with
By clicking “Sign in”, you agree to our Terms of Use & Privacy Policy