setup

test cos(pi) is -1
test cos(2 * pi / 3) is -0.5
test cos(pi / 2) is 0
test cos(pi / 3) is 0.5
test cos(0) is 1

//repeat with i = 0 to 90
//	test acos(cos(i / (2*pi))) is i / (2*pi)
//end repeat

teardown