not chim not chim. many functions are built in. just need to
re-map cos the original function has a Math object in front.
like:
var pi = Math.PI;
var e = Math.E;
function sin(x) { return Math.sin(x); }
function sind(x) { return Math.sin(x * pi/180); }
function log(x,y) { return Math.log(y)/Math.log(x); } where
Math.log(e) = 1.
the harder part is to parse it. for example, it does not recognise
"2pi", it'd have to be "2*pi". one way is to replace all "pi" with
"*pi", then replace all "**" (double multiply signs) with
"*".
but then, i realised, if my argument starts with "pi" then the code
wun work also. 
if i'm done i can try other functions like to find the root of a
function. 
