MaplePrimes - answers and comments on Question, Find the upper bound error using end point rule

Greatest in absolute value

Preben Alsholm — Thu, 13 Oct 2011 10:10:58 Z

f'' is not greatest in absolute value at -0.645, but at 0.218 (consistent with the graph) and found this way:

f:=(sin(x)+1)/(x^2+1);
numapprox:-infnorm(diff(f,x,x),x=-Pi/2..3*Pi/2,'xmax');
xmax;

Sorry. I still don't get how you got x =

Red Horse — Thu, 13 Oct 2011 21:07:04 Z

Sorry. I still don't get how you got x = .218. So the highest point in the graph isn't where the absolute value is greatest? Sorry if I'm still a little confused.

No

Preben Alsholm — Fri, 14 Oct 2011 10:41:54 Z

@Red Horse No, the greatest in absolute value can be seen on the plot of the absolute value:

plot(abs(diff(f,x,x)),x=-Pi/2..3*Pi/2);

@Preben Alsholm Cool. I finally

Red Horse — Fri, 14 Oct 2011 19:23:31 Z

@Preben Alsholm

Cool. I finally finished my project. Thank you so much for you help!