查看完整版本: ASL 數學與統計 極大和極小

ASL 數學與統計 極大和極小

f(x) = x+2

求遞增和遞減，可以的話請附圖。

求曲線y=5x^(2/3)-2x^(5/3)的轉向點。
點解去到當x=1 , y=3 / x =0 y=0 之後
dy/[url=http://hk.knowledge.yahoo.com/question/question?qid=7010072901296#]dx[/url] (x=0.5) = 10/3 •(1-0.5)/(0.5)^(1/3) > 0

dy/dx (x=1.5) = 10/3 •(1-1.5)/(1.5)^(1/3) < 0

(1,3)是極大點

究竟 0.5 同 1.5係點黎？

dy/dx (x=-0.5) < 0

dy/dx (x=0.5) > 0

(0,0)是極小點

究竟 -0.5 同 0.5係點黎？

THANKS

-0.5 and 0.5 are turning points of the curve.

You have to determine the sign of dy/dx in the intervals
x<0, 0<x<1 and x>1.

-0.5, 0.5 and 1.5 are just convenient choices.

You may consider other values of x in the relevant interval.