Unit Circle & Trig. Functions

Front

What is 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. It is used to define trigonometric functions for all angles.

Front

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

Back

(1, 0)

Front

What is the sine function in relation to the unit circle?

Back

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

Front

What is the cosine function in relation to the unit circle?

Back

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

Front

What is the tangent function in relation to the unit circle?

Back

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

Front

What is the value of sin(π/2)?

Back

1

Front

What is the value of cos(π)?

Back

-1

Front

What is the value of tan(0)?

Back

0

Front

What is the relationship between radians and degrees?

Back

Radians and degrees are two units for measuring angles. 180 degrees is equal to π radians.

Front

What is the value of cot(θ)?

Back

Cotangent is the reciprocal of tangent: cot(θ) = 1/tan(θ).