Question

A population of lizards in alarge region doubles every year.The number of lizards can bemodeled by the equationy= 500 - 2%, where x is thenumber of years after a researchermeasures the population size.When x= -3, what does the valueof y represent?

Answer 1

The population size of lizards can be determined as,

`y=500\cdot2^x`

Substituting the value x=-3.

The population size is,

`\begin{gathered} y=500\cdot(2)^(-3) \\ =62.5 \end{gathered}`

Thus, the required population size is 62.5.

It represent the population of the lizard 3 years prior to the researcher measures the population size.