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Let f(x) = x^(2) + px +q. The value of(p...

Let `f(x) = x^(2) + px +q`. The value of(p, q) so that f(1) =3 is an extreme value of f on [0, 2] is

A

`(-2,2)`

B

`(1,4)`

C

`(-2,4)`

D

`(-2,3)`

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The correct Answer is:
To solve the problem, we need to find the values of \( p \) and \( q \) such that \( f(1) = 3 \) is an extreme value of the function \( f(x) = x^2 + px + q \) on the interval \([0, 2]\). ### Step 1: Set up the function and conditions We have: \[ f(x) = x^2 + px + q \] We need to ensure that: 1. \( f(1) = 3 \) 2. \( f'(1) = 0 \) (since \( f(1) \) is an extreme value) ### Step 2: Calculate \( f(1) \) Substituting \( x = 1 \) into the function: \[ f(1) = 1^2 + p(1) + q = 1 + p + q \] Setting this equal to 3: \[ 1 + p + q = 3 \] This simplifies to: \[ p + q = 2 \quad \text{(Equation 1)} \] ### Step 3: Calculate the derivative \( f'(x) \) The derivative of \( f(x) \) is: \[ f'(x) = 2x + p \] Now, substituting \( x = 1 \): \[ f'(1) = 2(1) + p = 2 + p \] Setting this equal to 0 for the extreme value condition: \[ 2 + p = 0 \] This simplifies to: \[ p = -2 \quad \text{(Equation 2)} \] ### Step 4: Substitute \( p \) into Equation 1 Now, substitute \( p = -2 \) into Equation 1: \[ -2 + q = 2 \] Solving for \( q \): \[ q = 2 + 2 = 4 \quad \text{(Equation 3)} \] ### Step 5: Final values of \( p \) and \( q \) Thus, the values of \( p \) and \( q \) are: \[ p = -2, \quad q = 4 \] ### Conclusion The final answer is: \[ (p, q) = (-2, 4) \]
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