The label hypotenuse always remains the same — it’s the longest side. trigonometry definition: 1. a type of mathematics that deals with the relationship between the angles and sides of…. See more. The Period goes from one peak to the next (or from any point to the next matching point):. A function of an angle, or of an abstract quantity, used in trigonometry, including the sine, cosine, tangent, cotangent, secant, and cosecant, and their hyperbolic counterparts. A trigonometric function, also called a circular function, is a function of an angle. See more. The following indefinite integrals involve all of these well-known trigonometric functions. First, you have a usual unit circle. It is also the longest side. 1. Cosine (cos): Cosine function of an angle (theta) is the ratio of the adjacent side to the hypotenuse. Sine is usually abbreviated as sin. We’ll start this process off by taking a look at the derivatives of the six trig functions. (Here, and generally in calculus, all angles are measured in radians; see also the significance of radians below.) 2. b is the length of the side next to the angle θ and the right angle. The trigonometric functions relate the angles in a right triangle to … The basic trig functions can be defined with ratios created by dividing the lengths of the sides of a right triangle in a specific order. Trig Cheat Sheet Definition of the Trig Functions Right triangle definition For this definition we assume that 0 2 p <