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∘)=05 \sin(3\phi + 10^\circ) + 2 \cos(3\phi + 10^\circ) = 05sin(3ϕ+10∘)+2cos(3ϕ+10∘)=0
giving your answers to one decimal place.
A periodic voltage signal V V\,V follows the model
5sin2t−8cost=25 \sin^2 t - 8 \cos t = 25sin2t−8cost=2
Find 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.