Trigonometry is the branch of mathematics that deals with the solution of triangles through the use of the trigonometric functions sine, cosine, tangent and their reciprocals. The trig function values derive from the ratios of the "x" and "y" values of a point on a unit circle (radius r = 1.0) on the cartesian coordinate system starting with the 1st quadrant. Considering the trig functions of the angle "µ" formed by the radius "r" and the "x" axis; the sine(µ) = y/r; the cosine(µ) = x/r; and the tangent(µ) = y/x. Similarly, the sine(90 - µ) = x/r; the cosine(90 - µ) = y/r; and the tangent(90 - µ) = x/y. The reciprocals of the sine, cosine and tangent are coscecant, secant and cotangent respectively.
