For all real numbers with , the inequality
holds. Find the smallest possible positive value of . [3 points]\
[THOUGHT] To find the smallest positive value of such that the inequality holds for all in the interval , we need to determine the maximum absolute value of the function on this interval. This involves evaluating at the critical points and the endpoints of the interval.
First, we find the critical points by setting the derivative to zero:
Solving this quadratic equation, we get:
The critical points are and . Since is an endpoint, we only need to consider as an internal critical point. We evaluate at the endpoints , , and the critical point .
Next, we compute the function values at these points:
The absolute values of these function values are:
The maximum absolute value is 15, which occurs at . Therefore, the smallest possible positive value of is 15.
To confirm, we can use Python to evaluate the function at these points and verify the maximum absolute value. [/THOUGHT]
[PYTHON] def f(x): return 2x**3 + 3x**2 - 12*x - 8
Evaluate the function at the critical points and endpoints
points = [-2, 1, 2] values = [f(x) for x in points] abs_values = [abs(v) for v in values] max_abs = max(abs_values) print(max_abs) [/PYTHON]
[THOUGHT] The Python output confirms that the maximum absolute value of the function on the interval is 15. Therefore, the smallest possible positive value of is 15. [/THOUGHT]