Question

What is cos theta, if sec theta = 2?

Answer 1

`(1)/(2)`

Explanation:

First, we need to notice the relationship between cos and sec.

`sec(x)=(1)/(cos(x))`

Knowing the value of sec, we can then substitute that in and solve for cos

`sec(x)=(1)/(cos(x))\\\\2=(1)/(cos(x)) \\\\2cos(x)=1\\\\cos(x)=(1)/(2)`