Evaluate cosine sum and difference identity given as expression

The video tutorial explains how to calculate the cosine of specific angles, such as 31 and 1 degrees, by recognizing and applying a formula for the cosine of angle differences. The instructor guides students through the process of combining angles within the cosine function and clarifies the operations involved. The tutorial concludes with a review of the steps and a final clarification to ensure understanding.

Why is it challenging to calculate the cosine of 31 degrees directly?

• Because it is a negative angle.

• Because it is not on the unit circle.

• Because it requires breaking down into smaller angles.

• Because 31 degrees is not a standard angle.

What does the formula discussed in the video represent?

• Cosine of the sum of two angles

• Cosine of the difference of two angles

• Cosine of a single angle

• Cosine of a right angle

How can the cosine of 31 degrees minus 1 degree be simplified?

• As cosine of 31 degrees

• As cosine of 1 degree

• As cosine of 32 degrees

• As cosine of 30 degrees

What operation is applied inside the function to simplify the expression?

• Addition

• Multiplication

• Subtraction

• Division

What is the result of the cosine of 30 degrees?

• 0.5

• 1

• 0

• 0.866