Page 4: Continuation of Solutions
This page continues with solutions to the remaining problems.
Solution to Problem 3
The correctness of the mathematical statements is evaluated:
a) The statement is incorrect. For a local extremum at x=b, f'(b) must equal 0, not be non-zero.
b) The statement is false. Cubic functions always have at least two extrema (one maximum and one minimum).
c) The statement is correct. Every saddle point is indeed an inflection point, as it represents a change in concavity.
Definition: An inflection point is a point on a curve at which the curvature changes sign, from concave upwards to concave downwards or vice versa.
Solution to Problem 4
The solution for the function family f(x) = x³ - 4t·x² + 4t²·x is provided:
a) For t = -1, the zeros are calculated: x₁ = 0, x₂ = 2, x₃ = -2
b) To have a zero at x₁ = 6, t must equal 3.
Vocabulary: Nullstellen berechnen (calculating zeros) is a fundamental skill in function analysis, crucial for understanding the behavior of functions.
Solution to Problem 5
The solution demonstrates how to determine the parameter t for the function f(x) = x³ + 3x² + 3tx + 1 to have exactly two points with horizontal tangents:
The value of t is calculated to be -3, and an example function satisfying this condition is provided.
Highlight: This solution showcases the application of Funktionsschar Parameter bestimmen techniques to achieve specific function characteristics.