A-LevelMathematicsTrigonometry9709/12 · Feb/Mar 2016 · Q46 Marks
Solve the equation sin⁻¹(3x) = −π/6, giving the solution in an exact form.
- (a)Solve the equation sin⁻¹(3x) = −π/6, giving the solution in an exact form.[2]
- (b)Solve, by factorising, the equation 2 cos θ sin θ – 2 cos θ – sin θ + 1 = 0 for 0 < θ ≤ π.[4]
Mark scheme
Marking points from the official mark scheme (Feb/Mar 2016). The mark or mark type is shown in brackets.
- [M1] 3x = sin(-π/6) = -√3/2 (Accept -0.866 at this stage)
- [A1] x = -√3/6 oe (Or -3/(6√3) or -1/(2√3))
- [M1] Reasonable attempt to factorise and solve, e.g. (2 cos θ - 1)(sin θ – 1) = 0
- [A1] cos θ = 1/2 or sin θ = 1 (Award B1B1 www)
- [A1] θ = π/3
- [A1] θ = π/2
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →