Intro to the Unit Circle

• cosθ

• OP, the radius length

• sinθ

• 1

sin 0

• 0

• 1

• -1

• und

cos 0

• 0

• -1

• 1

• und

What is a complete circle in radians?

• π

• 2π

• 1/2 π

• 1

Which coordinate relates to the cosine of an angle?

• x-coordinate

• y-coordinate

• neither

How many degrees is ^π/₄ radians?

• 30°

• 45°

• 60°

• 90°

How many degrees is ^π/₂ radians?

• 30°

• 45°

• 60°

• 90°

What is half a circle in radians?

• π/4

• π

• 2π

• π/2

What is the radius of the unit circle?

• 0

• 1

• 1/2

• √2/2

Convert π radians to degrees.

• 90⁰

• 180⁰

• 360⁰

• 60⁰