In the closed interval [0, 3], the minimum value of the function f given below is:
f(x) = 2x3 −9x2 +12x
Correct Answer :
0
Solution :
The correct option is 0.
To find the minimum value of the function in the closed interval [0, 3], we need to evaluate the function at its critical points within the interval and at the endpoints of the interval.
Step 1: Find the critical points of the function.
A critical point occurs where the first derivative is equal to zero or is undefined.
Let's find the first derivative of with respect to :
Now, set the derivative to zero to find the critical points:
Divide the entire equation by 6 to simplify:
Factor the quadratic equation:
This gives the critical points:
and
Both of these critical points, and , lie within the given closed interval [0, 3].
Step 2: Evaluate the function at the critical points and the endpoints.
We need to calculate at , , , and .
1. At the left endpoint, :
2. At the critical point, :
3. At the critical point, :
4. At the right endpoint, :
Step 3: Compare the values to find the absolute minimum.
Comparing the calculated values of :
-
-
-
-
The smallest of these values is 0, which occurs at the endpoint . Therefore, the minimum value of the function on the closed interval [0, 3] is 0.
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