Question

Which function has a domain of all real numbers except x=π/2 ±nπ?

A. y=secx
B. y=cosx
C. y=1/sinx
D. y=cotx

Answer 1

Ok, well, what trig function is 0 at all odd multiples of pi/2 ?

1 divided by that function will be the function you are looking for.

Answer 2

so B?

Answer 3

yes. B

cos(pi/2) = 0
sec(x) = 1/cos/(x)

1/0 = impossible, unless you're chuck norris

Answer 4

Cosine x is the function that is 0 at odd multiples of pi/2

But you want the function that is 1/cos(x)

Answer 5

Not B.

Answer 6

oh. Sorry. I meant answer A
sec(x)

Answer 7

thanks!

Answer 8

y=sec x