Quick trigonometry question?

Question

What is the value of sec(π/2) (or sec(90°))? I used my calculator to find the value of cos(π/2), which is 0. So is sec(π/2) 0 as well or is it undefined, since secant is the reciprocal of cosine?

Answer 1

If cos(π/2) is 0, then sec(π/2) = 1/0, which is undefined.

Answer 2

sec(π/2) is undefined, since you can't take the reciprocal of 0.  If you look at the graph of sec(x), it has an asymptote at x = π/2.

Answer 3

sec(π/2) is not defined ( it is not infinity, just undefined ), because division by zero is not possible.

[as sec(x) = 1 / cos (x) and here cos (π/2) = 0.]

Answer 4

sec(π/2) = infinite

because sec = 1/cos

              sec (π/2) = 1/cos(π/2) = 1/ 0 = infinite