Learn how to evaluate using the sum formula of two angles cosine

The video tutorial explains the cosine formula and how to break down angles for evaluation. It covers the importance of understanding the unit circle and how to evaluate angles in different quadrants. The tutorial also demonstrates simplifying trigonometric expressions using algebraic methods, emphasizing the need to know the unit circle and trigonometric identities.

What is the first step in using the cosine formula for two angles?

• Identify the sine values

• Use the tangent formula

• Identify angles U and V

• Convert angles to radians

In which quadrant is the angle 120 degrees located, and what is its reference angle?

• First quadrant, 30 degrees

• Fourth quadrant, 90 degrees

• Third quadrant, 45 degrees

• Second quadrant, 60 degrees

How is the cosine value affected in the second quadrant?

• It becomes positive

• It doubles

• It becomes negative

• It remains the same

What is essential to know when evaluating trigonometric expressions?

• The sine rule

• The quadratic formula

• The unit circle

• The Pythagorean theorem

What is the final step in simplifying trigonometric expressions?

• Adding all terms

• Dividing by the largest term

• Multiplying fractions and combining terms

• Subtracting the smallest term