All flashcards
Flashcard 1: What is the significance of f′(x)=0?
Answer: Potential local max, min, or saddle point. Zero derivative indicates a horizontal tangent line at that point.
Flashcard 2: What does the second derivative of a function indicate?
Answer: The concavity of the function. f′′(x) describes whether the graph curves upward or downward.
Flashcard 3: What does a positive f′′(x) indicate about f(x)?
Answer: The graph of f(x) is concave up. Positive second derivative means the graph curves upward like a bowl.
Flashcard 4: Find f′′(x) for f(x)=x4−4x2+6.
Answer: f′′(x)=12x2−8. Differentiate twice using power rule: (x4)′′=12x2, (−4x2)′′=−8.
Flashcard 5: State the definition of an inflection point.
Answer: Where f′′(x) changes sign. Inflection points occur where concavity changes from up to down or vice versa.
Flashcard 6: What is the first derivative of f(x) used to determine?
Answer: The slope of the tangent line to f(x). f′(x) represents the instantaneous rate of change at any point.
Flashcard 7: Identify the intervals of increase for f(x)=x2−4x+3.
Answer: Increasing on (2,infinity). Find where f′(x)=2x−4>0, so x>2.
Flashcard 8: What is the relationship between f(x) and f′(x)?
Answer: f′(x) gives the slope of f(x). The derivative measures how steeply the function rises or falls.
Flashcard 9: Identify the local minimum of f(x)=x2−4x+4.
Answer: Local minimum at x=2. Complete the square: f(x)=(x−2)2, minimum at vertex.
Flashcard 10: Compute f′′(x) for f(x)=x5−5x3+10x.
Answer: f′′(x)=20x3−30x. Differentiate twice: f′(x)=5x4−15x2, then f′′(x)=20x3−30x.
Flashcard 11: What is the effect of f′(x)=0 on f(x)?
Answer: Potential local extremum. Zero derivative creates a horizontal tangent, possibly an extremum.
Flashcard 12: What can be concluded if f′(x)>0?
Answer: f(x) is increasing on that interval. Positive first derivative means function values are getting larger.
Flashcard 13: What is the relationship between f′′(x) and concavity?
Answer: f′′(x)>0: concave up; f′′(x)<0: concave down. Second derivative test determines the direction of curvature.
Flashcard 14: What does f′′(x)>0 imply about f(x)?
Answer: Function is concave up. Positive second derivative indicates the function curves upward.
Flashcard 15: Calculate f′(x) for f(x)=x3−3x+1.
Answer: f′(x)=3x2−3. Apply power rule: derivative of x3 is 3x2, derivative of −3x is −3.
Flashcard 16: Calculate f′′(x) for f(x)=x3−3x2+1.
Answer: f′′(x)=6x−6. Differentiate twice: f′(x)=3x2−6x, then f′′(x)=6x−6.
Flashcard 17: What does f′′(x)=0 suggest about f(x)?
Answer: Possible inflection point. Zero second derivative may indicate where concavity changes.
Flashcard 18: What occurs at a local minimum of f(x)?
Answer: f′(x)=0 and f′′(x)>0. Both conditions ensure a true local minimum exists.
Flashcard 19: Find inflection points for f(x)=x3−3x+1.
Answer: Inflection point at x=0. Set f′′(x)=6x=0 to find where concavity changes.
Flashcard 20: What does f′(x)<0 imply about f(x)?
Answer: f(x) is decreasing on that interval. Negative first derivative means function values are getting smaller.
Flashcard 21: What does a negative f′′(x) indicate?
Answer: The graph is concave down. Negative second derivative means the graph curves downward.
Flashcard 22: Find the critical points for f(x)=x2−4x+3.
Answer: Critical points: x=2. Set f′(x)=2x−4=0 to find x=2.
Flashcard 23: What is the critical point of a function f(x)?
Answer: Where f′(x)=0 or f′(x) is undefined. Critical points occur where the derivative equals zero or doesn't exist.
Flashcard 24: Determine where f(x)=−x3+3x2 is decreasing.
Answer: Decreasing on (0,2). Find where f′(x)=−3x2+6x=−3x(x−2)<0.
Flashcard 25: When does f(x) have a point of inflection?
Answer: When f′′(x) changes sign. Sign change in second derivative indicates concavity reversal.
Flashcard 26: What is the significance of f′(x)=0?
Answer: Potential local max, min, or saddle point. Zero derivative indicates a horizontal tangent line at that point.
Flashcard 27: When does f(x) have a point of inflection?
Answer: When f′′(x) changes sign. Sign change in second derivative indicates concavity reversal.
Flashcard 28: Determine where f(x)=−x3+3x2 is decreasing.
Answer: Decreasing on (0,2). Find where f′(x)=−3x2+6x=−3x(x−2)<0.
Flashcard 29: What does a negative f′′(x) indicate?
Answer: The graph is concave down. Negative second derivative means the graph curves downward.
Flashcard 30: What does f′(x)=0 imply about f(x)?
Answer: Possible local max, min, or point of inflection. Zero derivative indicates a horizontal tangent line.