Question

Exposure to ionizing radiation is known to increase the incidence of cancer. One thousand laboratory rats are exposed to identical doses of ionizing radiation, and the incidence of cancer is recorded during subsequent days. The researchers find that the total number of rats that have developed cancer t months after the initial exposure is modeled by for months. Find the rate of growth of the number of cancer cases at the 7th month.

Answer 1

Missing information :

The model was omitted from the question ; the possible model relating to the question was browsed online and could possibly be :

N(t) = 1.07t^2.3 for 0 ≤ t ≤ 10 months

Answer:

30.9 cases per month

Explanation:

Given the model to determine the number of rats that have developed cancer after initial exposure ; N(t) = 1.07t^2.3

N(t) = 1.07t^2.3

Take the first derivative of N with respect to t to obtain the rate of change ;

N'(t) = (1.07)(2.3)t^2.3-1

N'(t) = (1.07)(2.3)t^1.3

The rate of growth of cancer cases at the 7th month can be calculated thus :

t = 7

N'(7) = (1.07)(2.3)t^1.3

N'(7) = 1.07 * 2.3 * 7^1.3

N'(7) = 1.07 * 2.3 * 12.549529

N'(7) = 30.884

The rate of growth of cancer at the 7th month is 30.9 cases per month.