I am trying to model population growth using trig models... I am looking for models of the form $$\frac{a+b\sin x + c\cos x}{d + e\sin x + f\cos x}$$ or similar... The graphs I am trying to model are shown in the picture!
Any ideas of any functions I can use to get these shapes? I've done a bit of trial and error in desmos, but I have no strategy other than trial and error and it hasn't been successful so far...
Thanks!