You can use 2 alternative ways. But, with built-in math. functions defined on R (as e.g. sin), you have to write the argument as a float number (see gkokovidis 2063 answer)

1. As an expression, while using variable assignment:

   f := 2*sin(x)-x^2/(10.00);  x := 5. ; f ; unassign('x')      gives  -4.417848549

Note: the command "unassing('x')" is just a precaution for not keeping the assigned value of 'x' fo further computations.

2. As a function: it's better for further use, as Kitonum 9667 says.

  f :=x->2*sin(x)-x^2/10.00;  f(5.)  gives -4.417848549

whereas f(5) gives only   2*sin(5)-2.500000000.

You can see the following: 

    sin(5) gives  sin(5);   else you have to do  evalf(sin(5)) to obtain the value.

whereas sin(5.) directly gives -.9589242747 ;

Dear mj17515

I apologize, but solving differential equations is really not my cup of tea, and I do not even know the Differential Transform Method. In these conditions (as usual, as one finds almost always answer in the Web :), I typed in Google: "Differ.…..Method" and obtained several linsks, e.g.:

http://www.m-hikari.com/ams/ams-2011/ams-69-72-2011/mirzaeeAMS69-72-2011-2.pdf.  It includes much explications and theorems, where one can see Dirac delta function is effectively involved in some cases.

http://www.sciencedirect.com/science/article/pii/S0307904X07002247.  The donwload is free, and in ref. list, the #[16] indicates method using Maple !  Its download is not free, but you get it if you have university bib. commodities. Just for curiosity: For what subject, do you need this equation?

JLP

Note: there are much infos on differ. equ. in Help pages of Maple.

Hi,

Maybe the help page "Dirac" could answer your 1st question. The Dirac function is applied by "Dirac (opts)",

it can be one-dimensional, k-dimensional, nth derivative, ...