Ify=2x^3+18x^2-20for0≤x≤10,themaximumvalueofyoccurswhenx=A)0B)1.13C)6D)8.87E)10Choice(C)isthecorrectanswertoquestion3.Youcanuseagraphingcalculatortohelpyousolvetheproblem.Graphtheequationinanappropriatevi

Question

If y=2x^3+18x^2-20 for 0≤x≤10,the maximum value of y occurs when x=
A) 0
B) 1.13
C) 6
D) 8.87
E) 10
Choice (C) is the correct answer to question 3.You can use a graphing calculator to help you solve the problem.Graph the equation in an appropriate viewing window that allows you to see the maximum value of Y.You can do this by setting the values of x from 0 to 10 and then selecting a zoom option that fits the y-values for the given x-values.Once you graph the equation,use the "maximum" feature of the calculator to find the maximum value of y on the interval 0≤x≤10.You can see from the graph that the max value of y is 196,which occurs when x=6.It is important to remember that the minimum or maximum values do not have to occur at the endpoints of the domain interval.

Answer 1

你题目有问题吧,应该是y=-2x^3+18x^2-20,三次方为负,才可能在x=6时,y取得最大值.
可以用求导来解答