Plane Trigonometry. Spherical Trigonometry. In this article, let us discuss the six important trigonometric functions, ratios, trigonometry table, formulas and identities which helps to find the missing angles or sides of a right triangle. Trigonometry Ratios-Sine, Cosine, Tangent. sin(x -y)=s in(x) cos(y) -cos(x)sin(y) cos(x -y) = cos(x) cos(y)+sin(x)sin(y) tan(x) -tan(y) tan(x -y)= 1 + tan(x) tan(y) LAW OF SINES sin(A) sin(B) sin(C) = = a b c. DOUBLE-ANGLE IDENTITIES sin(2x)=2s in(x) cos(x) cos(2x) = cos 2 (x) -sin 2 (x) = 2 cos 2 (x) 1 =1-2sin 2-(x) 2 tan(x) tan(2x)= 1 -tan 2 (x) HALF-ANGLE IDENTITIES r ⇣ ⌘x 1 cos Laws and theorems. Sines. Cosines. Tangents. Cotangents. Pythagorean theorem. Calculus. Trigonometric substitution. Integrals ( inverse functions) Derivatives. v. t. e. In mathematics, sine and cosine are trigonometric functions of an angle. For right-angled triangles, the ratio between any two sides is always the same and is given as the trigonometry ratios, cos, sin, and tan. Trigonometry can also help find some missing triangular information, e.g., the sine rule. This page explains the sine, cosine, tangent ratio, gives on an overview of their range of values and provides practice problems on identifying the sides that are opposite and adjacent to a given angle. The Sine, Cosine and Tangent functions express the ratios of sides of a right triangle. Trigonometry. Share. Watch on. The Graphs of Sin, Cos and Tan - (HIGHER TIER) The following graphs show the value of sinø, cosø and tanø against ø (ø represents an angle). From the sin graph we can see that sinø = 0 when ø = 0 degrees, 180 degrees and 360 degrees. Sine, Cosine and Tangent (often shortened to sin, cos and tan) are each a ratio of sides of a right angled triangle: For a given angle θ each ratio stays the same. no matter how big or small the triangle is. To calculate them: Divide the length of one side by another side. Example: What is the sine of 35°? Generalized trigonometry. Reference. Identities. Exact constants. Tables. Unit circle. Laws and theorems. Sines. Cosines. Tangents. Cotangents. Pythagorean theorem. Calculus. Trigonometric substitution. Integrals ( inverse functions) Derivatives. v. t. e. zthX.