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Find the absolute maximum and minimum values of f(x) = 2x³ - 9x² - 60x + 4 on the interval [-3, 1].

1 Answer

4 votes

Final Answer:

  • The absolute maximum value of
    f(x) on interval
    [-3,1] is
    72 at
    x=-2.
  • The absolute minimum value of
    f(x) on interval
    [-3,1] is
    -63 at
    x=1.

Step-by-step explanation:

To find the absolute maximum and minimum values of the function
f)x)=2x^(3)-9x^2-60x+4 on the interval
[-3,1], we'll follow these steps:

  1. Find the Derivative: This will help us locate the critical points, where the slope of the function is zero or undefined.
  2. Identify Critical Points: Solve
    f'(x)=0 and check for any points where
    f'(x) is undefined.
  3. Evaluate the Function at Critical Points and Endpoints: We'll plug these points into
    f(x) to find the corresponding y-values.
  4. Determine the Absolute Maximum and Minimum: The highest and lowest y-values from step 3 are the absolute maximum and minimum, respectively.

Let's start by finding the derivative of
f(x).

Step 1: Find the Derivative


f(x)=2x^3-9x^2-60x+4

The derivative,
f'(x), is:


f'(x)=(d)/(dx)(2x^3)- (d)/(dx)(9x^2)-(d)/(dx)(60x)+(d)/(dx)(4)

Now, let's calculate this derivative.

The derivative
f'(x) is:


f'(x)=6x^2-18x-60

Step 2: Identify Critical Points

To find the critical points, we solve
f'(x)=0. This means we need to solve the equation:


6x^2-18x-60=0

Let's solve this quadratic equation for
x.

The critical points are
x=-2 and
x=5. However, since we are only interested in the interval
[-3,1], we can ignore
x=5 as it is outside this range.

Step 3: Evaluate the Function at Critical Points and Endpoints

We need to evaluate
f(x) at the critical point
x=-2 and the endpoints of the interval,
x=-3 and
x=1. This will give us the function values at these points.

Let's calculate
f(-2),
f(-3), and
f(1).

The function values at the critical point and endpoints are:


  • f(-2)=72

  • f(-3)=49

  • f(1)=-63

Step 4: Determine the Absolute Maximum and Minimum

  • The absolute maximum value of
    f(x) on interval
    [-3,1] is
    72 at
    x=-2.
  • The absolute minimum value of
    f(x) on interval
    [-3,1] is
    -63 at
    x=1.

These are the highest and lowest values the function attains in the given interval.

answered
User Scott Persinger
by
8.6k points
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