Trigonometry

Trigonometry involves the relationships between the sides and angles of right-angled triangles.

Functions

	H = hypotenuse (always opposite the right-angle)
	O = opposite (opposite the angle theta)
	A = adjacent (next to the angle theta)

	sine(theta) =  O   cosine(theta) =  A    tangent(theta) =  O
		      ---		   ---			  ---
		       H		    H			   A

	cosecant(theta) =  1/sine(theta)
	secant(theta) = 1/cosine(theta)
	cotangent(theta) = 1/tangent(theta)

Identities

Where t and u are angles:

sin(90deg - t) = cos(t)

cos(90deg - t) = sin(t)

sin(t)/cos(t) = tan(t)

sin^2(t) + cos^2(t) = 1

sin(2t) = 2sin(t)cos(t)

cos(2t) = cos^2(t) - sin^2(t)

sin(t +/- u) = sin(t)cos(u) +/- cos(t)sin(u)

cos(t +/- u) = cos(t)cos(u) -/+ sin(t)sin(u)

Graphical Interpretations