Carbon-14 is present in all living things. When a living thing dies, the amount of isotope at that time starts to decay.
The function for radioactive decay is R(t)=R0(1/2)t/h, where R is the radioactivity/gram of carbon-14 at time t after death, R0 is the radioactivity/gram of carbon at the time of death, and h is the half-life of carbon-14. The half-life of carbon-14 is 5370 years. After 3000 years, how much carbon-14 radioactivity/gram remains in a dead tree?
So far I've set up the equation:
But how are you supposed to solve for R(t) when you have 2 unknowns?