Cambridge IGCSE Additional Mathematics · Syllabus 0606 · Trigonometry
Complete Solution Set
What is Complete Solution Set?
A complete solution set is every angle in the stated domain that satisfies the equation, with no angle omitted and none included that does not satisfy it or that lies outside the domain. Because trigonometric functions are periodic and many-to-one, a single calculator value is only the reference angle; the complete set is built by combining that reference angle with the quadrants in which the function has the required sign, and then adding or subtracting whole periods until the domain is exhausted. Completeness is the whole requirement, so a correct method that stops at one angle has not answered the question.
This definition is part of the Trigonometry chapter in Cambridge IGCSE Additional Mathematics.