So there are:
SinA: stands for sine. The ratio of the opposite side of angle α to the hypotenuse,
Sina = account
CosA: for cosine. The ratio of adjacent straight edges to the hypotenuse of angle α,
cosA=b/c
Tana: It means tangent. The ratio of the opposite side of angle A to the adjacent straight side, tana = a/b.
CtanA: indicates cotangent. The ratio of adjacent straight edges to opposite edges of Angle A, tana = b/a.
ArctanA: It means arc tangent.