written-working-preserving-solutions
Learning Focus 𝅛 Student Activity 𝅛 Exam-quality Working 𝅛 Teaching Notes 𝅛 Follow-up ⭕ Learning Focus SL and HL students: (no additional HL content) • recognising when an algebraic step may discard valid solutions • explaining why equal trigonometric outputs do not necessarily have equal inputs • factorising before applying the null-factor law • checking every solution against the stated domain • presenting a...