Bisect

Bisect is a verb meaning to divide something into two equal parts. In geometry, a bisector is a line, ray, or segment that divides another object into two congruent parts. The term comes from Latin bisectus, meaning cut in two.

In geometry, a segment bisector passes through the segment’s midpoint, and all points on the bisector are equidistant from the segment’s endpoints. An angle bisector passes through the vertex and splits the angle into two equal angles. A perpendicular bisector is a special type of bisector that is perpendicular to the segment at its midpoint, and the intersection point is equidistant from the segment’s endpoints. In triangles, angle bisectors and perpendicular bisectors have well-known properties and intersections with other lines and circles.

In mathematics and computer science, the bisection method, also known as binary search, is an algorithm for locating a target value within a sorted set or for finding a root of a function. It repeatedly halves the search interval, leading to logarithmic time complexity. For root finding, the method relies on the intermediate value theorem when the function is continuous and the interval endpoints have opposite signs.

In software development, the term appears in tools such as git bisect, which performs a binary search over the commit history to identify the commit that introduced a bug. The process involves designating a known good state and a known bad state and then testing midpoint revisions to narrow the range of suspect commits.