Calculus

Ancient geometers (i.e., mathematicians working on geometrical problems) was obsessed with two problems: (1) finding the area of planar shapes (e.g. the area of a circle) and (2) finding the tangent to a curve i.e., the line that touches the curve at only one point. Although some results were obtained, mostly by Archimedes with the method of exhaustion, a universal method that can be applied to any curves was not available until the early of the seventeenth century.