LEARN · EXPLAIN · REVISE

How many coterminal representatives of 30° lie in this closed interval?

Read the idea, work independently, then explain what changed.

TOPIC 01

Trigonometric functions: mixed assessment

A mixed assessment: identify the method, justify it and revise your reasoning.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Transfer#Your turn

[-3240^{\circ},3240^{\circ}]

Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1

Keep degrees and radians distinct and use the definition of angular measure.

Hint 2

Write every coterminal angle as 30°+360°n.

Worked solution

Keep degrees and radians distinct and use the definition of angular measure.
Calculate or simplify this relation.
$-3240\le30+360n\le3240\Rightarrow -9\le n\le8$
Integer n must satisfy both bounds.

The requested value is 18.

Checks and common pitfalls: Integer n must satisfy both bounds.

Think first. Reveal a hint when the class is ready.

Teacher preparation and assessment