Questions: Consider the function f(x) = 2x^3 + 15x^2 - 144x + 9 with -8 ≤ x ≤ 4 This function has an absolute minimum at the point and an absolute maximum at the point Note: both parts of this answer should be entered as an ordered pair, including the parentheses, such as (5,11).

Consider the function
f(x) = 2x^3 + 15x^2 - 144x + 9 with -8 ≤ x ≤ 4

This function has an absolute minimum at the point
and an absolute maximum at the point
Note: both parts of this answer should be entered as an ordered pair, including the parentheses, such as (5,11).
Transcript text: Consider the function \[ f(x)=2 x^{3}+15 x^{2}-144 x+9 \quad \text { with } \quad-8 \leq x \leq 4 \] This function has an absolute minimum at the point $\square$ and an absolute maximum at the point $\square$ Note: both parts of this answer should be entered as an ordered pair, including the parentheses, such as $(5,11)$.
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Solution

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Solution Steps

To find the absolute minimum and maximum of the function \( f(x) = 2x^3 + 15x^2 - 144x + 9 \) on the interval \([-8, 4]\), we need to:

  1. Find the critical points by taking the derivative of \( f(x) \) and setting it to zero.
  2. Evaluate \( f(x) \) at the critical points and at the endpoints of the interval.
  3. Compare these values to determine the absolute minimum and maximum.
Step 1: Find the Derivative

The function is given by

\[ f(x) = 2x^3 + 15x^2 - 144x + 9. \]

To find the critical points, we first compute the derivative:

\[ f'(x) = 6x^2 + 30x - 144. \]

Step 2: Solve for Critical Points

Next, we set the derivative equal to zero to find the critical points:

\[ 6x^2 + 30x - 144 = 0. \]

Factoring or using the quadratic formula, we find the critical points to be

\[ x = -8 \quad \text{and} \quad x = 3. \]

Step 3: Evaluate the Function at Critical Points and Endpoints

We evaluate \( f(x) \) at the critical points and the endpoints of the interval \([-8, 4]\):

  • At \( x = -8 \):

\[ f(-8) = 2(-8)^3 + 15(-8)^2 - 144(-8) + 9 = 1097. \]

  • At \( x = 3 \):

\[ f(3) = 2(3)^3 + 15(3)^2 - 144(3) + 9 = -234. \]

  • At \( x = 4 \):

\[ f(4) = 2(4)^3 + 15(4)^2 - 144(4) + 9 = -199. \]

Step 4: Determine Absolute Minimum and Maximum

Now we compare the values obtained:

  • \( f(-8) = 1097 \)
  • \( f(3) = -234 \)
  • \( f(4) = -199 \)

The absolute minimum occurs at \( (3, -234) \) and the absolute maximum occurs at \( (-8, 1097) \).

Final Answer

The absolute minimum is at the point \(\boxed{(3, -234)}\) and the absolute maximum is at the point \(\boxed{(-8, 1097)}\).

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