Sec(2x) is an abbreviation for the secant of 2 times x, where sec(x) represents the reciprocal of cosine (1/cos(x)).
Trigonometric Functions: Functions like sine, cosine, tangent, etc., which relate angles in a right triangle to ratios of side lengths.
Reciprocal Function: A function that gives us the multiplicative inverse of another function's output values.
Periodicity: The property of functions repeating their values after certain intervals or periods.