Sine and Cosine on the Unit Circle
Drag the point and activate the checkboxes to explore how the sine and cosine of an angle change sign and value on the unit circle, then answer the questions below the app.
Practice Zone
What are the signs of and ?
In which quadrant does lie? What are the signs of its sine and cosine?
An angle lies in the third quadrant. What is the sign of ?
How many angles (if any) have a sine equal to ? If they exist, what can you say about their positions in the unit circle?
How many angles (if any) have a cosine equal to ? If they exist, what can you say about their positions in the unit circle?
How many angles (if any) have a sine equal to ? If they exist, what can you say about their positions in the unit circle?