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The largest value of 2x^(3)-3x^(2)-12x+5...

The largest value of `2x^(3)-3x^(2)-12x+5` for `-2 le x le 2` occurs when

A

`x=-2`

B

`x=-1`

C

`x=2`

D

`x=0`

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To find the largest value of the function \( f(x) = 2x^3 - 3x^2 - 12x + 5 \) for \( -2 \leq x \leq 2 \), we will evaluate the function at the endpoints of the interval and at any critical points within the interval. ### Step 1: Find the derivative of the function First, we need to find the derivative of \( f(x) \): \[ f'(x) = \frac{d}{dx}(2x^3 - 3x^2 - 12x + 5) \] Using the power rule, we get: \[ f'(x) = 6x^2 - 6x - 12 \] ### Step 2: Set the derivative to zero to find critical points Next, we set the derivative equal to zero to find critical points: \[ 6x^2 - 6x - 12 = 0 \] Dividing the entire equation by 6 gives: \[ x^2 - x - 2 = 0 \] Now, we can factor the quadratic: \[ (x - 2)(x + 1) = 0 \] Thus, the critical points are: \[ x = 2 \quad \text{and} \quad x = -1 \] ### Step 3: Evaluate the function at the endpoints and critical points We will evaluate \( f(x) \) at \( x = -2, -1, 0, 2 \). 1. **At \( x = -2 \)**: \[ f(-2) = 2(-2)^3 - 3(-2)^2 - 12(-2) + 5 \] \[ = 2(-8) - 3(4) + 24 + 5 = -16 - 12 + 24 + 5 = 1 \] 2. **At \( x = -1 \)**: \[ f(-1) = 2(-1)^3 - 3(-1)^2 - 12(-1) + 5 \] \[ = 2(-1) - 3(1) + 12 + 5 = -2 - 3 + 12 + 5 = 12 \] 3. **At \( x = 0 \)**: \[ f(0) = 2(0)^3 - 3(0)^2 - 12(0) + 5 = 5 \] 4. **At \( x = 2 \)**: \[ f(2) = 2(2)^3 - 3(2)^2 - 12(2) + 5 \] \[ = 2(8) - 3(4) - 24 + 5 = 16 - 12 - 24 + 5 = -15 \] ### Step 4: Compare the values Now we compare the values we calculated: - \( f(-2) = 1 \) - \( f(-1) = 12 \) - \( f(0) = 5 \) - \( f(2) = -15 \) The largest value occurs at \( x = -1 \) where \( f(-1) = 12 \). ### Conclusion The largest value of \( f(x) \) for \( -2 \leq x \leq 2 \) occurs when \( x = -1 \). ---

To find the largest value of the function \( f(x) = 2x^3 - 3x^2 - 12x + 5 \) for \( -2 \leq x \leq 2 \), we will evaluate the function at the endpoints of the interval and at any critical points within the interval. ### Step 1: Find the derivative of the function First, we need to find the derivative of \( f(x) \): \[ f'(x) = \frac{d}{dx}(2x^3 - 3x^2 - 12x + 5) \] Using the power rule, we get: ...
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