Evaluate a trig function written as a sum or difference expression

The video tutorial explains how to solve a trigonometric problem without a calculator by recognizing patterns and applying the sum and difference formulas. The instructor guides students through the process of identifying the cosine of two angles and simplifying the solution using the order of operations.

Why can't the cosine of 37 degrees be directly evaluated in this scenario?

• The cosine function is undefined for this angle.

• The value is too complex to calculate.

• The angle is not in the standard position.

• A calculator is not available.

What is the purpose of recognizing patterns in trigonometric problems?

• To memorize all possible values.

• To avoid using any mathematical tools.

• To ensure all angles are acute.

• To simplify calculations using known formulas.

Which formula is used to simplify the problem involving cosine of two angles?

• Quadratic Formula

• Law of Sines

• Sum and Difference Formula

• Pythagorean Theorem

How is the cosine of 45 degrees calculated in this example?

• Using a calculator

• Using the tangent function

• By applying the sum formula

• By estimating the value

What is the simplified value of cosine 45 degrees?

• Square root of 3 divided by 2

• Square root of 2 divided by 2

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