Question
upstudy study bank question image url

Find the inlervals on which the graph of I is concave upward, the intorvals on which tho graph off is concave downward, and the inflection points \[ f(x)=x^{3}-18 x^{2}+2 x+2 \] For what inlerval(s) of \( x \) is the graph of \( I \) concave upward? Select the correct duice bebw and, if necessary, fill in the answer box lo complete your chnice A. \( (6, \infty) \) (Type your answer in inleval notalion. Type an exacl answer. Uso a comna to separato answers as noodod.) B. The graph is never concave upward. Fot what inlerval(\$) of \( x \) is the graph of 1 concave downward? Select the conect choica below and, il necessary, fill in the answer hox to complete your choico. A. \( (-\infty, 6) \) (Type your answer in inlerval notation. Type an viacl answer. Use a comma to soparate answers as needed.) B. The graph is never concave downward. Delermine the \( x \), \( y \) coordinates of the inflection point of the graph of \( f \). Solect the correct choice below and, if necessary, fil in the answer box to complete your choice A. \( \square \) (Typs an ondered pair.) B. There are no inlloction ponts.

Ask by Romero Wheeler. in the United States
Mar 11,2025

Upstudy AI Solution

Tutor-Verified Answer

Answer

The graph of \( f(x) = x^3 - 18x^2 + 2x + 2 \) is concave upward on \( (6, \infty) \), concave downward on \( (-\infty, 6) \), and has an inflection point at \( (6, -418) \).

Solution

**Step 1. Find the second derivative.** Given \[ f(x)=x^3-18x^2+2x+2, \] first, compute the first derivative: \[ f'(x)=3x^2-36x+2. \] Then, compute the second derivative: \[ f''(x)=6x-36. \] **Step 2. Determine concavity.** - The graph is concave upward where \( f''(x)>0 \). Set up the inequality: \[ 6x-36>0. \] Dividing both sides by 6: \[ x-6>0 \quad \Longrightarrow \quad x>6. \] So, the graph is concave upward on \( (6,\infty) \). - The graph is concave downward where \( f''(x)<0 \). Set up the inequality: \[ 6x-36<0. \] Dividing both sides by 6: \[ x-6<0 \quad \Longrightarrow \quad x<6. \] So, the graph is concave downward on \( (-\infty,6) \). **Step 3. Find the inflection point.** An inflection point occurs where the concavity changes, i.e., where \( f''(x)=0 \). Set \( f''(x)=0 \): \[ 6x-36=0 \quad \Longrightarrow \quad x=6. \] Find the corresponding \( y \)-coordinate by evaluating \( f(6) \): \[ f(6)=6^3-18\cdot 6^2+2\cdot 6+2. \] Calculate step by step: \[ 6^3=216, \quad 6^2=36 \quad \Longrightarrow \quad 18\cdot 36=648, \] \[ f(6)=216-648+12+2= (216+12+2)-648 =230-648=-418. \] Thus, the inflection point is at \[ (6,-418). \] **Final Answers:** - The graph is concave upward on \( (6,\infty) \). - The graph is concave downward on \( (-\infty,6) \). - The inflection point is \((6,-418)\).

Answered by UpStudy AI and reviewed by a Professional Tutor

error msg
Explain
Simplify this solution

Beyond the Answer

To determine where the graph of the function \( f(x) = x^3 - 18x^2 + 2x + 2 \) is concave upward or downward, we need to analyze its second derivative. The first derivative \( f'(x) = 3x^2 - 36x + 2 \), and the second derivative \( f''(x) = 6x - 36 \). Setting the second derivative to zero gives us \( x = 6 \). Thus, the graph is concave upward on \( (6, \infty) \) and concave downward on \( (-\infty, 6) \). The inflection point occurs where the concavity changes, which is at the coordinate \( (6, f(6)) \). We calculate \( f(6) = 6^3 - 18 \cdot 6^2 + 2 \cdot 6 + 2 = -86 \). Therefore, the inflection point is \( (6, -86) \). Concavity is all about the change! Fun fact: concavity relates to how the slopes of tangent lines behave on the graph—if they are getting steeper (upward) or less steep (downward). This concept is widely applicable in fields like economics, where understanding whether returns on investment accelerate or decelerate can significantly impact strategy and planning.

Related Questions

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