Determine the phase angles ϕ\phiϕ, in the range −60∘<ϕ<60∘-60^\circ < \phi < 60^\circ−60∘<ϕ<60∘, that satisfy the following equilibrium condition for a mechanical oscillator:
5sin(3ϕ+10∘)+2cos(3ϕ+10∘)=0 5 \sin(3\phi + 10^\circ) + 2 \cos(3\phi + 10^\circ) = 0 5sin(3ϕ+10∘)+2cos(3ϕ+10∘)=0giving your answers to one decimal place.
A periodic voltage signal V V\,V follows the model
5sin2t−8cost=2 5 \sin^2 t - 8 \cos t = 2 5sin2t−8cost=2Find all values of t t\,t in the range 0<t<2π 0 < t < 2\pi\,0<t<2π for which this model holds, giving your answers to 3 significant figures.
137 exam-style questions on Edexcel A Level Maths Trigonometry and Modelling, covering 7.1 Addition Formulae, 7.2 Double Angle Formulae, 7.3 Solving Trigonometric Equations, 7.4 Simplifying a cos x +- b sin x, 7.5 Proving Trigonometric Identities, and 7.6 Modelling with Trigonometric Functions. Each one has a worked solution and a mark scheme showing where the marks go.