Questions: A function f has derivative f'(x)=x(x+3) e^x, and a critical point at x=0.
Classify the critical point.
LOCAL MAXIMUM
LOCAL MINIMUM
NOT A LOCAL EXTREMUM
Transcript text: A function $f$ has derivative $f^{\prime}(x)=x(x+3) e^{x}$, and a critical point at $x=0$.
Classify the critical point.
LOCAL MAXIMUM
LOCAL MINIMUM
NOT A LOCAL EXTREMUM
Solution
Solution Steps
To classify the critical point at \( x = 0 \), we need to analyze the second derivative \( f''(x) \). If \( f''(0) > 0 \), the critical point is a local minimum. If \( f''(0) < 0 \), the critical point is a local maximum. If \( f''(0) = 0 \), the test is inconclusive.
Step 1: Find the Second Derivative
The first derivative of the function is given by
\[
f'(x) = x(x + 3)e^x.
\]
To classify the critical point at \( x = 0 \), we need to compute the second derivative \( f''(x) \). The second derivative is calculated as follows:
\[
f''(x) = f'(x) + \text{additional terms from the product rule}.
\]
After simplification, we find that
\[
f''(0) = 3.
\]
Step 2: Classify the Critical Point
To classify the critical point at \( x = 0 \), we evaluate \( f''(0) \):
If \( f''(0) > 0 \), then \( x = 0 \) is a local minimum.
If \( f''(0) < 0 \), then \( x = 0 \) is a local maximum.
If \( f''(0) = 0 \), the test is inconclusive.
Since \( f''(0) = 3 > 0 \), we conclude that \( x = 0 \) is a local minimum.
Final Answer
The classification of the critical point is \\(\boxed{\text{LOCAL MINIMUM}}\\).