This page explores the derivatives of trigonometric functions in calculus. Interactive calculus applet.

Definition and properties of a chord - a line segment that joins two points on the circumference of a circle

The angle made by two secants that intersect outside a circle is half the difference between the intercepted arc measures.

States: When two secant lines intersect each other outside a circle, the products of their segments are equal.

Introduction to the 6 trigonometry functions - sine, cosine, tangent, secant, cosecant, cotangent

A pictorial index to the parts of a circle. A diagram with links to full definitions.

Definition of secant function in trigonometry as applied to right triangles

Definition and properties of a secant - a line that intersects a circle at two points