resoudre sin(t+pi/5)=sin(pi/5)

sin(t+π/5)=sin(π/5)
donc t+π/5=π/5+2kπ ou t+π/5=π-π/5+2kπ
donc t=0+2kπ ou t=3π/5+2kπ
donc S={2kπ;3π/5+2kπ/k∈Z}