Topic: Show values on the graph
I am trying to teach the Trapezium rule and I want to show the value for each of the points. Anyone know if this is possible?
If there is some way of splitting the graph into trapeziums too then that would be amazing!
Re: Show values on the graph
First you need a straight line function, which is given by two points. Insert it as your custom function:
line(x,x1,y1,x2,y2) = x*(y2-y1)/(x2-x1) + (x2*y1 - x1*y2)/(x2 - x1)
Than you have some function to play with, for example, another custom funtion:
curve(a) = a + sin a ;
Following picture shows a result. You can have as many line(x,.....) functions as you wish.
Post's attachments
Trapez.grf 959 b, 562 downloads since 2012-04-18
trapez.png 35.16 kb, 570 downloads since 2012-04-18
Re: Show values on the graph
ooh lovely, thanks. What about showing the point values?
4 2012-04-18 20:21:02 (edited by pin 2012-04-18 20:31:45)
Re: Show values on the graph
Yes, it's not difficult.
1. Select your function;
2. Menu "Calc" -> "Table";
3. Insert x-value for the first point "From", last point "To", step "Δx", and press "Calc";
4. Select cells in x-column and f(x) column, and copy the selection into clipboard: Ctrl-C; close the table;
5. Menu "Function"-> "Insert point series", paste the clipboard in table (clear text "x" and "f(x)" if shown in the first row);
6. Select styles for Marker and Line;
7. Check the box "Show coordinates", and select required position;
8. Press OK, finished.
Post's attachments
Trapez2.grf 1.15 kb, 575 downloads since 2012-04-18