Trigonometryhard · Past Paper
If sin A + sin B = x and cos A + cos B = y, then tan((A+B)/2) is:
Ax/y
By/x
Cx+y
Dxy
✓ Correct Answer: A — x/y
Dividing (2 sin((A+B)/2) cos((A-B)/2)) by (2 cos((A+B)/2) cos((A-B)/2)) gives tan((A+B)/2) = x/y.
Share this question
More from Trigonometry
- The angles of elevation of the top of a tower from two points on the ground at distances 4 m and 9 m from the base are complementary. Tower height?
- The expression 4 cos^3 A - 3 cos A equals:
- Simplify (1 + sin 2A + cos 2A) / (1 + sin 2A - cos 2A).
- Evaluate: 5 sin^2 30 + cos^2 45 - 4 tan^2 30
- If tan θ + cot θ = 2, find the value of tan²θ + cot²θ.