### Home > A2C > Chapter 8 > Lesson 8.1.4 > Problem8-64

8-64.

Sketch a unit circle. In your circle, sketch in an angle that has: 7-63 HW eTool (Desmos).

1. A positive cosine and a negative sine.

2. A sine of $−1$.

3. A negative cosine and a negative sine.

4. A cosine of about $−0.9$ and a sine of about $0.4$.

5. Could an angle have a sine equal to $0.9$ and cosine equal to $0.8$? Give an angle or explain why not.

Use the eTool below to explore these ideas.
Click the link at right for the full version of the eTool: CCA2 7-63 HW eTool