Understanding Negative Angles in Trigonometry

The video tutorial explains negative angles on the Cartesian plane, focusing on how they are measured in the clockwise direction. It covers the renumbering of the CAST diagram to accommodate negative angles and discusses the behavior of trigonometric functions like sine, cosine, and tangent in different quadrants. The tutorial provides examples and predictions to illustrate these concepts, emphasizing the simplicity of understanding negative angles by adjusting the CAST diagram and considering the direction of measurement.

What is the direction of measurement for negative angles on the Cartesian plane?

• Counterclockwise

• Vertically

• Horizontally

• Clockwise

If an angle is -30°, from which axis do we start measuring?

• Positive x-axis

• Negative y-axis

• Positive y-axis

• Negative x-axis

In the renumbered CAST diagram, what is the angle at the third quadrant?

• 180°

• 90°

• 360°

• 270°

What is the new angle for the fourth quadrant in the renumbered CAST diagram?

• 0°

• 90°

• 180°

• 360°

In which quadrant does the angle 180° minus Theta lie?

• Second quadrant

• First quadrant

• Third quadrant

• Fourth quadrant

What is the sign of the sine function for angles in the second quadrant?

• Positive

• Zero

• Negative

• Undefined

How is the angle 180° plus Theta classified in terms of quadrants?

• Second quadrant

• Third quadrant

• First quadrant

• Fourth quadrant

Where do negative acute angles appear on the Cartesian plane?

• First quadrant

• Second quadrant

• Third quadrant

• Fourth quadrant

What is the sign of the cosine function for negative acute angles in the fourth quadrant?

• Positive

• Negative

• Zero

• Undefined

Which trigonometric function remains positive in the fourth quadrant?

• Cosecant

• Tangent

• Cosine

• Sine