Indian Mathematics c6.10

c6.10

They are followed by a table of 24 sines progressing by intervals of 3° 45′ obviously taken from Ptolemy’s table of chords. Instead, however, of dividing the radius into 60 parts, as did Ptolemy, Pauliśa divides it into 120 parts; for as sin (α)/2 = (chord α)/2 this division of the radius enabled him to convert the table of chords into sines without numerical change. Āryabhata gives another measure for the radius (3438') which enabled the sines to be expressed in a sort of circular measure.