Definition:Tangent to Curve/Historical Note

Historical Note to Tangent to Curve
The definition of the tangent to a curve as the limit of a sequence of secants was made by.

It first appeared in his, but the idea most probably dates from considerably earlier.

This definition anticipates the invention of differential calculus.

In fact,, in a letter that was discovered as late as $1934$, specifically states that it was the work of which inspired his own ideas about calculus.