微积分I(标准路径) · 免费预览
§3.3 Using derivatives to identify extreme values (continued)
函数 $f$ 的临界数是什么?它们与确定该函数所能取得的最极端的值之间有什么联系?
1. Summary
Summary
2. Sign chart from a derivative graph
A graph of shows negative for , positive for , and positive for , with . The function has
3. Inflection points from the same graph
The same graph of shows horizontal tangents at about and , with steepest between them. The inflection points of occur at
4. A plateau that is neither peak nor valley
Suppose and on both and . At the function has
5. What is special about the flat point
With , nearby, and existing on , the value is special because
6. Roots of a function from its derivative graph
A graph of shows for and for , with tending to as . If has two distinct real solutions, their signs must be
7. Long run appearance of the graph
With the same approaching as , the graph of for large looks like
8. A rational derivative with a vertical asymptote
Let with having a vertical asymptote at . The critical numbers of and their classification are
9. Long term behavior from a rational derivative
For the same , the value of and its meaning are
10. Second derivative test with a formula
Let . The critical number lies between and , so has
11. Inflection inventory
With the same , the inflection points of occur at
12. Tangent line above or below at an inflection
The point lies on with , and is an inflection point. The tangent line at lies
13. Evaluating the second derivative
For , compute .
14. Locating the golden ratio critical number
The critical number appears in the study of . Compute its decimal value, rounded to three places.
15. Inflection needs a sign change
If and changes sign at , then has an inflection point at .