2 past paper questions on trigonometry from NSC, 2020. Read what each one asks, then open it with its memo.
Questions
2 questions on trigonometry. Each opens in the question browser with its memo.
2020 · Paper 2 · September · NSC · Question 5, 6
Evaluate cos 79° cos 311° + sin 101° sin 49° without a calculator, prove tan x = 2 tan y from sin(x + y) = 3 sin(x − y), then prove an identity in cos 2x and sin 2x and use it to solve an equation on [0°; 360°]. The second question reads a sine and a cosine graph over [−90°; 360°]: find the four parameters, the period, and the values of x satisfying two conditions, one involving both derivatives.
compound anglesdouble anglesproving identitiesgeneral solutiontrigonometric graphsperiodreading a graph
Open this question
2020 · Paper 2 · September · NSC · Question 7
A three-dimensional problem. P, Q and R lie in the same horizontal plane with PR = QR = m and angle QPR = x, SP is perpendicular to PQ, and the angle of elevation of S from Q is y. Express the area of triangle PQR in terms of x and m, show that PQ = 2m cos x, and hence prove that SP = 2m cos x tan y.
three dimensionsarea ruleisosceles triangleangle of elevationproof in terms of variables
Open this question
Next topic
Carry on through the Grade 12 curriculum.
Euclidean geometry past paper questions
Descriptions last updated 10 August 2026.