Chapter 4: Problem 7
Draw the given angles. $$50^{\circ},-120^{\circ},-30^{\circ}$$
Short Answer
Expert verified
50° is counterclockwise; -120° and -30° are clockwise.
Step by step solution
01
Understanding the Positive Angle
To draw a positive angle like \(50^{\circ}\), start from the positive x-axis (the right side of the horizontal line) and rotate counterclockwise. The angle \(50^{\circ}\) means you rotate 50 degrees in the counterclockwise direction. Draw this angle in standard position starting from the positive x-axis.
02
Understanding a Negative Angle
For negative angles, such as \(-120^{\circ}\), rotation is done clockwise. Begin at the positive x-axis and rotate clockwise to reach the desired angle. For \(-120^{\circ}\), imagine starting from zero and moving clockwise 120 degrees to reach the final position of the angle.
03
Drawing the -30° Angle
To draw \(-30^{\circ}\), start again from the positive x-axis, and then rotate clockwise by 30 degrees. This slightly less than quarter circle brings the terminal side below the x-axis in the fourth quadrant.
Unlock Step-by-Step Solutions & Ace Your Exams!
-
Full Textbook Solutions
Get detailed explanations and key concepts
-
Unlimited Al creation
Al flashcards, explanations, exams and more...
-
Ads-free access
To over 500 millions flashcards
-
Money-back guarantee
We refund you if you fail your exam.
Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Positive Angles
A positive angle is formed by a counterclockwise rotation starting from the positive x-axis. These angles indicate a turn in the direction opposite to that of a clock's hands. For example, a positive angle of \(50^{\circ}\) means that you begin from the right side of the horizontal axis and rotate upwards along a circular arc. Positive angles range from \(0^{\circ}\) to \(360^{\circ}\) in a single full rotation.
To draw a \(50^{\circ}\) angle:
To draw a \(50^{\circ}\) angle:
- Start on the positive x-axis.
- Measure 50 degrees counterclockwise from this starting point.
- The terminal side will be slightly above the 0-degree line in the first quadrant.
Negative Angles
Negative angles involve rotation in a clockwise direction, starting from the positive x-axis. They typically indicate a rotation that goes in the same direction as a clock's hands. For example, when dealing with a negative angle like \(-120^{\circ}\), the movement is downward from the starting line.
Here's how to interpret a \(-120^{\circ}\) angle:
Here's how to interpret a \(-120^{\circ}\) angle:
- Begin at the positive x-axis direction (the familiar starting point for angle measurement).
- Rotate clockwise for 120 degrees.
- The terminal side of this angle will rest within the third quadrant.
Clockwise Rotation
Clockwise rotation implies turning a figure in the direction that the hands on a clock move. For drawing angles, it's particularly relevant when dealing with negative angles. When you have an angle labeled with a negative sign, like \(-30^{\circ}\), you'll make a clockwise movement from the positive x-axis.
To create a \(-30^{\circ}\) angle:
To create a \(-30^{\circ}\) angle:
- Start on the positive x-axis.
- Rotate 30 degrees in a clockwise direction.
- This positions the terminal side in the fourth quadrant, just below the horizontal axis.
Counterclockwise Rotation
Counterclockwise rotation points in a direction opposite to that of a clock's hands. It's the default orientation for positive angles. This means if an angle has no negative sign, it rotates counterclockwise from the positive x-axis.
Understanding a counterclockwise rotation:
Understanding a counterclockwise rotation:
- Begins at the positive x-axis.
- Moves upward through the quadrants based on the degree of the angle.
- For example, a \(50^{\circ}\) angle moves slightly into the first quadrant.