In the past, the number of fish in a pond could be modelled by the function P(t)=7000-2000sin((pi/6)t) where t is the number of months after January. However, because of a lack of fishermen since the start of the new year, the number of fish in the pond has been increasing at a rate of 35 per month. If this pattern continues, which of these functions could now be used to model the number of fish in the pond?

a)R(t)=7000+35t-2000sin((pi/6)t)
b)R(t)=7000-2035sin((pi/6)t)
c)R(t)=7000-2000sin((pi/6)(t+35))
d)R(t)=7035-2000sin((pi/6)t)

1 answer

35fish/month means that after t months you get an extra 35t fish, right?
so, which choice reflects that?