Definition:Sine/Historical Note

Historical Note on Sine
It was who first compiled tables relating the length of the arc of a circle and the length of the chord which gives rise to it, for various angles subtended by the arc.

However, he did not actually define the concept of a sine as such.

The sine was first discussed by, under the name ardha-jyā, which means half-chord.

The symbol $\sin$ for sine appears to have been invented by in his $1657$ work Trigonometrie, although some authors attribute it to.