@Carl Love 

Point taken. I have two new methods of getting k.

With either I get the correct value for tod

cheers

@Carl Love 

Enouraged by your comments I have a better worksheet

Your comments on Plot were most helpful

Thanks

@Carl Love 

changed t to x to allow plot

thanks for comments

Sorry, it does work (Maple 2017)

I had corrected a typo and forgot to click the Excute tool

I'm a Maple novice, much more comfortable (at the moment) with SMath (a freebee)

best wishes

This works

Round:= (x,n)-> parse(sprintf(sprintf("%%.%df",n),x));

This does not

Round := (x,n) -> parse(sprintf("%.*f",n,x)):

@Mariusz Iwaniuk 

Many thanks. Using the dot I now get the required answer

I canot see the use of multiply but will soldier on