Solve, for 0<θ<360∘0 < \theta < 360^\circ0<θ<360∘, the equation 4sin(θ+40∘)=3cos(θ+40∘)4 \sin(\theta + 40^\circ) = 3 \cos(\theta + 40^\circ)4sin(θ+40∘)=3cos(θ+40∘) giving your answers to one decimal place.
Show that the equation 2sin3x=6sinx−5sinxcosx2 \sin^3 x = 6 \sin x - 5 \sin x \cos x2sin3x=6sinx−5sinxcosx can be written in the form sinx(acos2x+bcosx+c)=0\sin x (a \cos^2 x + b \cos x + c) = 0sinx(acos2x+bcosx+c)=0 where aaa, bbb and ccc are constants to be found.
Hence solve for −π≤x≤π-\pi \le x \le \pi−π≤x≤π the equation 2sin3x=6sinx−5sinxcosx2 \sin^3 x = 6 \sin x - 5 \sin x \cos x2sin3x=6sinx−5sinxcosx giving your answers to two decimal places where appropriate.
Practise Edexcel A Level Maths 7.3 Solving Trigonometric Equations with exam-style questions for A Level Maths. 29 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.