1. Explain why csc 180° is undefined.
2. Show that the value of sin increases as θ goes from 0° to 90° and then decreases as goes from 90° to 180°.
3. Math Journal Draw a unit circle. Use the drawing to complete the chart below that indicates the sign of the trigonometric functions in each quadrant.
![1872_6cad00c3-5bb0-4319-aeba-5b3f9d7a1f9b.png](https://secure.tutorsglobe.com/CMSImages/1872_6cad00c3-5bb0-4319-aeba-5b3f9d7a1f9b.png)