Evaluate for sine cosine and tangent using reference angles

The video tutorial explains how to evaluate the sine, cosine, and tangent of -840 degrees using coterminal and reference angles. It covers the concept of negative angles, finding reference angles both graphically and algebraically, and calculating trigonometric values. The tutorial emphasizes the importance of understanding the unit circle and the properties of angles in different quadrants.

What is the first step in evaluating trigonometric functions for an angle like -840 degrees?

• Use a calculator to find the values.

• Find the reference angle directly.

• Determine the terminal side on the unit circle.

• Convert the angle to radians.

How can you find a coterminal angle for -840 degrees?

• Add or subtract 360 degrees until the angle is positive.

• Multiply the angle by 2.

• Divide the angle by 2.

• Add 180 degrees to the angle.

What is the reference angle for -840 degrees?

• 30 degrees

• 45 degrees

• 60 degrees

• 90 degrees

In which quadrant does the terminal side of -840 degrees lie?

• First quadrant

• Fourth quadrant

• Second quadrant

• Third quadrant

What is the sine of -840 degrees?

• -sqrt 3 / 2

• 1/2

• -1/2

• sqrt 3 / 2

What is the cosine of -840 degrees?

• -sqrt 3 / 2

• 1/2

• -1/2

• sqrt 3 / 2

What is the tangent of -840 degrees?

• -sqrt 3

• 1

• sqrt 3

• -1