Lösung 1.3:1c
Aus Online Mathematik Brückenkurs 2
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- | The function has zero derivative at three points, | + | The function has zero derivative at three points, <math>x=a</math>, <math>x=b</math> and <math>x=c</math> (see picture below), which are therefore the critical points of the function. |
- | <math>x=a</math>, | + | |
- | <math>x=b</math>and | + | |
- | <math>x=c</math> | + | |
- | (see picture below), which are therefore | + | |
[[Image:1_3_1_c1.gif|center]] | [[Image:1_3_1_c1.gif|center]] | ||
- | The point | + | The point <math>x=b</math> is an inflexion point because the derivative is positive in a neighbourhood both to the left and right. |
- | <math>x=b</math> | + | |
- | is an inflexion point because the derivative is positive in a neighbourhood both the left and right. | + | |
- | At the left endpoint of the interval of definition and at | + | At the left endpoint of the interval of definition and at <math>x=c</math>, the function has local maximum points , because the function takes lower values at all points in the vicinity of these points. At the point <math>x=a</math> and the right endpoint, the function has local minimum points. |
- | <math>x=c</math>, the function has local maximum points , because the function takes lower values at all points in the vicinity of these points. At the point | + | |
- | <math>x=a</math> | + | |
- | and the right endpoint, the function has local minimum points | + | |
- | + | ||
- | + | ||
- | + | ||
- | + | ||
+ | Also, we see that <math>x=c</math> is a global maximum (the function takes its largest value there) and the right endpoint is a global minimum. | ||
[[Image:1_3_1_c2.gif|center]] | [[Image:1_3_1_c2.gif|center]] | ||
- | Between the left endpoint and | + | Between the left endpoint and <math>x=a</math>, as well as between <math>x=c</math> |
- | <math>x=a</math>, as well as between | + | and the right endpoint, the function is strictly decreasing (the larger <math>x</math> is, the smaller <math>f(x)</math> becomes), whilst the function is strictly increasing between <math>x=a</math> and <math>x=c</math> (the graph flattens out at <math>x=b</math>, but it isn't constant there). |
- | <math>x=c</math> | + | |
- | and the right endpoint, the function is strictly decreasing (the larger | + | |
- | <math>x</math> | + | |
- | is, the smaller | + | |
- | <math>f | + | |
- | becomes), whilst the function is strictly increasing between | + | |
- | <math>x=a</math> | + | |
- | and x=c (the graph flattens out at | + | |
- | <math>x=b</math>, but it isn't constant there). | + | |
- | + | ||
[[Image:1_3_1_c3.gif|center]] | [[Image:1_3_1_c3.gif|center]] |
Version vom 12:03, 17. Okt. 2008
The function has zero derivative at three points,
The point
At the left endpoint of the interval of definition and at
Also, we see that
Between the left endpoint and