Unit Circle Concepts and Functions

The video tutorial introduces trigonometry, focusing on the unit circle and trigonometric functions. It explains the conversion between degrees and radians, and how to calculate sine, cosine, and tangent using the unit circle. The tutorial also covers quadrantal angles and provides AP style questions for practice.

What is the angle in radians for a full circle?

• π radians

• 2π radians

• π/2 radians

• 3π/2 radians

How many degrees are equivalent to π radians?

• 270°

• 360°

• 180°

• 90°

What is the radius of a unit circle?

• 2

• π

• 1

• 0

In a unit circle, what does the y-coordinate represent?

• Tangent

• Sine

• Cosine

• Radius

Which function is undefined at 90° or π/2 radians?

• Tangent

• Sine

• Secant

• Cosine

What are the coordinates of the point at 0° on the unit circle?

• (0, -1)

• (0, 1)

• (1, 0)

• (-1, 0)

What is the sine of 180° or π radians?

• Undefined

• -1

• 1

• 0

What is the cosine of 270° or 3π/2 radians?

• Undefined

• 0

• 1

• -1

If the radius of the circle is 3, what would be the x-coordinate of the point at 0°?

• 1

• 0

• Undefined

• 3

What happens to the tangent function at 90° or π/2 radians?

• It is zero

• It is one

• It is negative

• It is undefined