Pre-Calculus - Evaluting for cosine of the difference of two angles cos195

The video tutorial explains how to find the cosine of the difference between two angles using the unit circle and trigonometric identities. It begins with an introduction to the concept, followed by a detailed explanation of angles and the unit circle. The tutorial then demonstrates how to evaluate the cosine and sine of specific angles, leading to the calculation of the cosine of the angle difference using a formula. The video concludes with the final calculation and a summary of the process.

What is the representation of 195 degrees in terms of angle subtraction?

• 180 degrees minus 15 degrees

• 200 degrees minus 5 degrees

• 210 degrees minus 15 degrees

• 225 degrees minus 30 degrees

Where is the 30-degree angle located on the unit circle?

• At the top of the circle

• At the bottom of the circle

• On the right side of the circle

• On the left side of the circle

What are the coordinates for the angle 225 degrees on the unit circle?

• -1/2, -sqrt 3 / 2

• -sqrt 2 / 2, -sqrt 2 / 2

• 1/2, sqrt 3 / 2

• sqrt 3 / 2, 1/2

Which formula is used to calculate the cosine of the difference between two angles?

• cos(U - V) = sin(U) * sin(V) - cos(U) * cos(V)

• cos(U - V) = sin(U) * cos(V) + cos(U) * sin(V)

• cos(U - V) = cos(U) * cos(V) - sin(U) * sin(V)

• cos(U - V) = cos(U) * cos(V) + sin(U) * sin(V)

What is the final simplified expression for the cosine of 225 degrees minus 30 degrees?

• sqrt 3 - 1

• -sqrt 3 + 1

• -sqrt 3 - 1

• sqrt 3 + 1