Trigonometric Functions and Angles

Mrs. A explains how to find the exact values of sine and cosine for specific angles using sketches and special triangles. The video covers finding the related acute angles for 240° and 135°, applying the CAST rule, and using special triangles to determine the sine and cosine values without a calculator.

What is the first step in finding the exact values for sine and cosine functions?

• Use a table of values

• Memorize the values

• Sketch the angle

• Use a calculator

In which quadrant does the angle 240° lie?

• Fourth quadrant

• First quadrant

• Third quadrant

• Second quadrant

How do you find the related acute angle for 240°?

• 240° minus 90°

• 240° minus 45°

• 240° minus 180°

• 240° minus 60°

What is the sine of 60° in terms of a special triangle?

• 1/2

• 1

• √2/2

• √3/2

What is the sign of the sine function in the third quadrant?

• Undefined

• Zero

• Negative

• Positive

In which quadrant does the angle 135° lie?

• Fourth quadrant

• Third quadrant

• Second quadrant

• First quadrant

How do you find the related acute angle for 135°?

• 180° minus 135°

• 135° minus 180°

• 135° minus 45°

• 135° minus 90°

What is the cosine of 45° in terms of a special triangle?

• 1

• 1/2

• √3/2

• √2/2

What is the sign of the cosine function in the second quadrant?

• Zero

• Negative

• Positive

• Undefined

What is the rationalized form of 1/√2?

• 1

• 1/2

• √2/2

• √3/2