AHL 3.8 (HL)—Unit circle and trigonometric equations Topic Practice
AHL 3.8 (HL)—Unit circle and trigonometric equations Topic Practice
Students practise solving trigonometric equations using unit circle symmetry, exact values, and identities like sin(2α) and cos(2α).
How this is tested
- solve a trigonometric equation over an interval by equating the two models
- derive cos(2α) = 1 − 2 sin²(α) by substituting cos²α = 1 − sin²α into the double-angle identity
- explain sin(2α) = 2 sin α cos α using rotation matrix composition or geometric unit circle reasoning