Question: is secx the same as 1/cos x?
Answer: Each of these functions are derived in some way from sine and cosine. The tangent of x is defined to be its sine divided by its cosine: tan x = sin x cos x . ... The secant of x is 1 divided by the cosine of x: sec x = 1 cos x , and the cosecant of x is defined to be 1 divided by the sine of x: csc x = 1 sin x .