Question

Check all that apply. Sec θ is undefined for θ = ____.

A. π
B. π/2
C. 0
D. 3π/2

I think it is B. and D.?

Please explain answer. Thank you!

Answer 1

you got it

Answer 2

hopefully you remember that sec(theta) = 1/(cos(theta))

Answer 3

whenever cos(theta) is 0, sec(theta) is undefined because you have a division by zero

Answer 4

cos(theta) is 0 when x = pi/2 + k*pi where k is an integer

in this case, use k = 0 and k = 1 to get x = pi/2 and x = 3pi/2