Thread: Finding constant

Suppose that P is a function which satisfies P'(t)=rP(t) for some constant r and P(t+11)=4P(t)


Find r.


How do i start this?

Originally Posted by Velvet Love

Suppose that P is a function which satisfies P'(t)=rP(t) for some constant r and P(t+11)=4P(t)


Find r.


How do i start this?

I would start by integrating: dP/dt= rP(t) separates into dP/P= r dt.
Integrate both sides of that. Notice that P(t+11)= 4P(t) for all t. Take t= 0 to get an equation that will let you find r.

But wouldn't that mean r = 0?