If what is ?
We draw a right triangle. The tangent of x is t, which is the
same as t/1. The tangent is the opposite side over tha adjacent side,
so we make the opposite side of angle x be the numerator of t/1
which is t and the adjacent side be the denominator of t/1 which
is 1. That makes the hypotenuse be or .
The sine is the opposite over the hypotenuse and the cosine is the
adjacent over the hypotenuse, so
Edwin
