Trigonometry: Unit Circle

Front

What is the definition of the unit circle?

Back

The unit circle is a circle with a radius of 1 centered at the origin (0,0) in the coordinate plane.

Front

What are the coordinates of the point on the unit circle at an angle of 0 radians?

Back

(1, 0)

Front

What are the coordinates of the point on the unit circle at an angle of π/2 radians?

Back

(0, 1)

Front

What are the coordinates of the point on the unit circle at an angle of π radians?

Back

(-1, 0)

Front

What are the coordinates of the point on the unit circle at an angle of 3π/2 radians?

Back

(0, -1)

Front

How do you find the sine of an angle using the unit circle?

Back

The sine of an angle is the y-coordinate of the corresponding point on the unit circle.

Front

How do you find the cosine of an angle using the unit circle?

Back

The cosine of an angle is the x-coordinate of the corresponding point on the unit circle.

Front

What is the relationship between sine and cosine on the unit circle?

Back

For any angle θ, sin(θ) is the y-coordinate and cos(θ) is the x-coordinate of the point on the unit circle.

Front

What is the value of sin(π/6)?

Back

1/2

Front

What is the value of cos(π/3)?

Back

1/2