Trigonometric Function Values of Common Angles

This video tutorial covers the trigonometric function values of common angles using reference angles and triangles. It explains the relationships among the sides of 30-60-90 and 45-45-90 triangles, and demonstrates how to calculate the six trigonometric functions for angles like 120, 210, -45, and 270 degrees. The video also introduces the concept of the unit circle for quadrantal angles, providing exact values for sine, cosine, tangent, and their reciprocals.

What is the relationship among the sides of a 30-60-90 triangle?

• 1:2:√3

• 1:1:√2

• 1:√3:2

• 1:1:1

In a 45-45-90 triangle, what is the length of the hypotenuse if each leg is 1?

• √2

• 1

• 2

• √3

How is a reference angle formed?

• By the initial side and the y-axis

• By the terminal side and the closest part of the x-axis

• By the initial side and the x-axis

• By the terminal side and the y-axis

What is the sine of 120 degrees?

• 1/2

• √3/2

• -√3/2

• -1/2

What is the cosine of 120 degrees?

• -1/2

• √3/2

• 1/2

• -√3/2

What is the tangent of 210 degrees?

• -1

• 1

• -√3

• √3

What is the sine of -45 degrees?

• -√2/2

• √2/2

• -1

• 1

What is the cosine of -45 degrees?

• 1

• -1

• √2/2

• -√2/2

What is the sine of 270 degrees?

• -1

• 1

• Undefined

• 0

What is the tangent of 270 degrees?

• Undefined

• -1

• 1

• 0