Search results
The Greek letter θ (theta) is used as a variable in mathematics to represent an angle. The symbol appears in the three main trigonometric functions: cosine, sine, and tangent as an input argument.
Cosine. Cosine, written as cos(θ), is one of the six fundamental trigonometric functions. Cosine definitions. There are two main ways in which trigonometric functions are typically discussed: in terms of right triangles and in terms of the unit circle.
eometry and trigonometry are branches of mathematics concerned with geometrical figures and angles of triangles. The following list documents some of the most notable symbols in these topics, along with each symbol’s usage and meaning.
The sine and cosine of an acute angle are defined in the context of a right triangle: for the specified angle, its sine is the ratio of the length of the side that is opposite that angle to the length of the longest side of the triangle (the hypotenuse ), and the cosine is the ratio of the length of the adjacent leg to that of the hypotenuse.
The cosine function (or cos function) in a triangle is the ratio of the adjacent side to that of the hypotenuse. The cosine function is one of the three main primary trigonometric functions and it is itself the complement of sine(co+sine).
Therefore, the sign of a sine or cosine function is entirely determined by the signs of \(x\) and \(y\) for a point on the terminal side of the angle. \( \sin \theta =\dfrac{y}{r} \) \( \begin{array}{c|c}
Sine and cosine — a.k.a., sin(θ) and cos(θ) — are functions revealing the shape of a right triangle. Looking out from a vertex with angle θ, sin(θ) is the ratio of the opposite side to the hypotenuse, while cos(θ) is the ratio of the adjacent side to the hypotenuse.
