Evaluate cosine using the sum and difference formula

The video tutorial covers the application of the cosine addition formula, specifically for angles 60 and 45 degrees. The instructor emphasizes that while the addition will be provided during tests, students should be prepared to handle it independently in homework and future assessments. The tutorial includes a step-by-step evaluation of the cosine and sine values for these angles, highlighting common mistakes and the importance of careful calculation.

What will be provided in quizzes but not in homework according to the teacher?

• The formula sheet

• The addition or subtraction

• The unit circle

• The cosine values

In the cosine addition formula, what are the labels given to the angles?

• M and N

• U and V

• A and B

• X and Y

What is the cosine of 60 degrees as mentioned in the video?

• 1

• sqrt(2)/2

• 1/2

• sqrt(3)/2

What is the sine of 45 degrees according to the teacher?

• 1

• sqrt(2)/2

• sqrt(3)/2

• 1/2

Why does the teacher advise against doing calculations in your head?

• It is a rule in the class

• It is faster to write them down

• It helps avoid common mistakes

• It is required for the exam