Question

Which expression is equivalent to sec(–θ)?

sec θ

-sec θ

1/-cosθ

csc θ

Answer 1

sec(x)=1/cos(x)
you know that cos(-x)=cos(x) (cos-pi=cospi, cospi/2=cos-pi/2)
so sec(-x)=1/cos(x)=sec(x)

Answer 2

so whats the answer?

Answer 3

if you were following the proof, it would be the last line, thus sec(x)

Answer 4

technically im not even supposed to give the answer right away, just help you get to it