4A Unit Circle, Pythagorean Theorem & Identity

• 1

• 1

• -1

• 1

• y

• x

• x/y

• y/x

• y

• x

• x/y

• y/x

• y/r
• x/r
• r/y
• y/x

Use the unit circle to determine where

sinθ is positive in

• the 1st and 2nd quadrants
• the 1st and 3rd quadrants
• the 1st and 4th quadrants
• the 2nd and 3rd quadrants

What is the radius of the unit circle?

Use the unit circle

• 1

• 2

• 1/2

• 0

Use the unit circle to determine where

cosine is positive in

• the 1st and 2nd quadrants

• the 1st and 3rd quadrants

• the 1st and 4th quadrants

• the 2nd and 3rd quadrants