я Pi (3.1416) I Sigma (sign of summation) (I) Omega (angles measured in radians) a Acceleration due to gravity (32.16 ft. per A sec. per sec.) »' (or J) Imaginary quantity (,/П) sin Sine cos Cosine tan Tangent cot Cotangent see Secant CSC Cosccant vers Versed sine covcrs Covcrscd sine