What is the least value of the function f(x) = 2x2- 8x - 3 in the interval [ 0…
2013
What is the least value of the function f(x) = 2x2- 8x - 3 in the interval [ 0 , 5] ?
- A.
-15
- B.
7
- C.
-11
- D.
-3
Attempted by 13 students.
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Correct answer: C
To find the least value of f(x) = 2x^2 - 8x - 3 on the interval [0, 5], we first identify critical points.
The derivative is f'(x) = 4x - 8. Setting f'(x) = 0 gives x = 2, which lies within the interval [0, 5].
Evaluate f(x) at the critical point and endpoints: f(2) = -11, f(0) = -3, and f(5) = 7.
Comparing these values, the minimum value is -11.