### Home > PC > Chapter 4 > Lesson 4.3.2 > Problem 4-138

4-138.

Cosine is the *x*-value. Where on the unit circle is *x* = 1?

What θ gives a tangent of 1 or −1?

What quadrants would the tangent be −1?

Change the csc *θ* to 1/sin *θ*.

4-138.

Cosine is the *x*-value. Where on the unit circle is *x* = 1?

What θ gives a tangent of 1 or −1?

What quadrants would the tangent be −1?

Change the csc *θ* to 1/sin *θ*.