Unit Circle

Front

What is the Unit Circle?

Back

A circle with a radius of 1 centered at the origin of a coordinate plane, used to define trigonometric functions.

Front

What is the sine of an angle in the Unit Circle?

Back

The y-coordinate of the point on the Unit Circle corresponding to that angle.

Front

What is the cosine of an angle in the Unit Circle?

Back

The x-coordinate of the point on the Unit Circle corresponding to that angle.

Front

What is the tangent of an angle in the Unit Circle?

Back

The ratio of the sine to the cosine of that angle (tan(θ) = sin(θ)/cos(θ)).

Front

What are the coordinates of the point at 0 radians on the Unit Circle?

Back

(1, 0)

Front

What are the coordinates of the point at π/2 radians on the Unit Circle?

Back

(0, 1)

Front

What are the coordinates of the point at π radians on the Unit Circle?

Back

(-1, 0)

Front

What are the coordinates of the point at 3π/2 radians on the Unit Circle?

Back

(0, -1)

Front

In which quadrants is sin(θ) positive?

Back

In the 1st and 2nd quadrants.

Front

In which quadrants is cos(θ) positive?

Back

In the 1st and 4th quadrants.