BackCoterminal Angles and Expressions for All Coterminal Angles
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Q1. Give two positive and two negative angles that are coterminal with the given quadrantal angle.
Background
Topic: Coterminal Angles
This question tests your understanding of coterminal angles, which are angles that share the same terminal side when drawn in standard position. You need to find both positive and negative angles that are coterminal with a given angle (e.g., 90°, 180°, 0°, 270°).
Key Terms and Formulas:
Coterminal Angles: Angles that differ by integer multiples of 360°.
Formula: , where is any integer.
Step-by-Step Guidance
Start with the given angle (e.g., 90°).
To find positive coterminal angles, add 360° one or more times: , , etc.
To find negative coterminal angles, subtract 360° one or more times: , , etc.
Repeat this process for each given angle (180°, 0°, 270°).

Try solving on your own before revealing the answer!
Q2. Write an expression that generates all angles coterminal with each angle. Let n represent any integer.
Background
Topic: General Expression for Coterminal Angles
This question asks you to write a general formula for all angles coterminal with a given angle, using an integer variable (n) to represent all possible multiples of 360°.
Key Terms and Formulas:
Coterminal Angles: Angles that differ by integer multiples of 360°.
General Expression: , where is any integer.
Step-by-Step Guidance
Identify the given angle (e.g., 30°, 45°, 135°, etc.).
Write the expression for each angle, replacing with the specific angle value.
Explain that can be any integer, so this formula generates all possible coterminal angles (both positive and negative).
Apply this formula to each angle listed in the question.

Try solving on your own before revealing the answer!
Final Answer:
For Q1: Two positive coterminal angles for 90° are 450° and 810°, two negative coterminal angles are -270° and -630°. Repeat for other angles.
For Q2: The expression for all coterminal angles with 30° is , for 45° is , etc., where is any integer.
This formula ensures you can generate every angle that shares the same terminal side as the original angle.