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)ex.
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)+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}}\\).