@Kitonum Thanks, I appreciate your effort for showing to steps to achieve the same effect with another method.

@gkokovidis This is exactly what I sought thanks for the illuminating post.

@gkokovidis Can I also use this command to plot a vertical line together with some other plot?

This should work, but what is name type anyway? Why is the former (omega) is name, whereas omega^2 is not a name?

@Kitonum 

Thanks this is exactly what I want to do.@Kitonum 

Actually I cannot provide a working example since I do not know how to do it in Maple 15. But let me try to illustrate it step by step:

1. You call fsolve with a list of equations to be solved, or you call fsolve with a one-parameter function which is evaluated at a number of points(in my case 3).
2. You get the solutions in list form and make and assignment x1= solution with the first value of the parameter, x2=solutiion with the second value of the parameter etc.

@Carl Love 

Thanks for the suggestions I will try them out. By the way I did not understand the second part of your statement. What I meant was to provide a set of equations into solve or fsolve and get the solutions in a listed form so that I can address them as sol_1, sol_2 etc. @acer 

@Preben Alsholm 

Thanks for your comment I understood that it does not work as intended since it is a transcendental function and there are asymptotes in the graph of tangent. Am I correct? Furthermore, can I use an interval with the command solve? Also is it possible to use solve with a list of parameters so that a number of solutions would be obtained for different values of the parameter?

@Markiyan Hirnyk This works but I think the diff command does not support differentiating wrt to a function of an independent variables.

@Kitonum Thanks for the answer in my case I do not use function definitions I have definitions of force components in terms of the x and y coordinates of two points. My worksheet is as follows:

Download trial.mw

Download trial.mw

What I mean is that I have a formula defined for the x-component of some force in terms of the x coordinate of two points. My goal is to differentiate not with respect to a coordinate of a single point but with respect to x coordinate of point 1 minus x coordinate of point 2. I attached a Maple 15 file (mw) to clarify it please have a look.

@acer Well thanks for your answer is there an easy way to convert a document into worksheet or vice versa to easily implement your method?

Thanks, but would my license become corrupted and do I have to uninstall the program from the former HDD or pay some fee for this process? I have run into these kind of problems with an earlier version of Maple so i am pretty prudent.

Thanks, but would my license become corrupted and do I have to uninstall the program from the former HDD or pay some fee for this process? I have run into these kind of problems with an earlier version of Maple so i am pretty prudent.

Thanks for the replies; my issue is the former, I am trying to enlarge fonts in an existing (built-in) Maplet. I devised changing the resolution of the monitor but it is very inconvenient to do so just to see a number in a certain Maplet. I conclude there isn't any method to adjust the size of the fonts used in Maplets, unfortunately. By the way would changing the font size in Windows affect the fonts used in Maplets too? I would be glad to hear the suggestions from a Maplesoft representative. Thanks