Note all trigonometric data are radians (not degrees)

cos(a) - cosine

sin(a) - sine

tan(a) - tangent

ctan(a) - cotangent

atan(a) - arctangent

asin(a) - arcsine

acos(a) - arccosine

atan2(y,x) - arctangent ⇒ y and x must be one dimensional signals; return one dimensional signal