# Sine - Chord - Tangent - Secant

All trigonometric functions can be derived from a simple picture using the (unit) circle and similar triangles. The value of any trigonometric function can found as a combination of values of any one trigonometric function evaluated at some related angles. For example: cosine and sine are related via: cos(Θ) = sin(90°-Θ) etc...
a) Find how all of the functions in the applet can be written in terms of only sine. Note: These functions are normally written as sine = sin chord = crd tangent = tan secant = sec b) Complete the diagram to include the complementary trigonometric functions. These functions are normally written as cosine = cos cotangent = cot cosecant = csc Hints: You can understand all of the relations by using similar triangles. The value of a complementary function is the value of the function evaluate at the complementary angle.