Trig Ratios on the X and Y-Axes: Using Coordinates of the Unit Circle

This video tutorial explains the trigonometric ratios of sine, cosine, and tangent using the unit circle. It covers how to determine these ratios at quadrantal angles, where either the x or y coordinate is zero. The tutorial also discusses the conditions under which trigonometric ratios are undefined, emphasizing the importance of recognizing these angles in both degrees and radians. The lesson concludes with a summary of key concepts and examples to reinforce understanding.

What is the sine of an angle at 90 degrees on the unit circle?

• -1

• 1

• Undefined

• 0

At which angle is the tangent of the terminal ray undefined?

• 0 degrees

• 90 degrees

• 180 degrees

• 270 degrees

What is the cosine of 180 degrees?

• -1

• Undefined

• 1

• 0

Which of the following angles has a tangent of 0?

• 270 degrees

• 90 degrees

• 180 degrees

• 360 degrees

What is the sine of 270 degrees?

• Undefined

• 0

• -1

• 1

Which trigonometric ratio is undefined when x is 0?

• Tangent

• Cosecant

• Sine

• Cosine

What is the relationship between tangent and the slope of the terminal ray?

• Tangent is the y-coordinate

• Tangent is the slope

• Tangent is undefined

• Tangent is the x-coordinate