a = {0,30,45,60,90,120,135,150,180,270,300,360}
tan(a)={ 0,1/√3,1,√3,∞ ,-√3,-1,-1/√3,0,∞ ,-√3,0}
tan(175) = -0.087489
cos(175) = -0.996195
sin(175) = 0.087156