Since TBASIC handles only integer there is no built-in Trig or Log functions which are really meant for floating point math.
You could however create a number of data points in a lookup table and search for the nearest 2 data point and use linear interpolation to get a refined result.
E.g. You can store the result of SIN(1) to SIN(90) in DM[1] to DM[90], represent each value as 1/10000.
therefore SIN(30) = 0.5 will be stored as 5000 in DM[30].
Now if you need to find the value of SIN(60.2)
DM[60] = 8660
DM[61] = 8746
Therefore SIN(60.2) = 8660+ 0.2*(8746-8660) = 8677
i.e. SIN(60.2) is approximated by 0.8677
Calculator check : SIN(60.2) = 0.8678 - not a bad approximation.
So you can write a custom function compute and return the SIN or any angle between 0 to 360 degree using the lookup table.
Note: In TBASIC you need to write the computation as
R = DM[60]+ 2*(DM[61]-DM[60])/10
(i.e. Multiplication must be before division to maximize the precision)
