Consider the following problem:The population of a town grows at a rate of r(t)=t2+2t people per year (where t is time in years). At time t=3, the town's population is 2300 people. By how much did the population grow between years 3 and 10 ?Which expression can we use to solve the problem?Choose 1 answer:(A) r(10)−r(3)(B) ∫310r(t)dt(C) ∫r(t)dt(D) 2300+∫310r(t)dt
Q. Consider the following problem:The population of a town grows at a rate of r(t)=t2+2t people per year (where t is time in years). At time t=3, the town's population is 2300 people. By how much did the population grow between years 3 and 10 ?Which expression can we use to solve the problem?Choose 1 answer:(A) r(10)−r(3)(B) ∫310r(t)dt(C) ∫r(t)dt(D) 2300+∫310r(t)dt
Calculate total growth: To find the growth of the population between years 3 and 10, we need to calculate the total increase over that period. The rate of growth is given by the function r(t)=t2+2t. We need to integrate this rate of growth from t=3 to t=10 to find the total increase in population.
Integral of growth rate: The correct expression to calculate the total growth of the population from year 3 to year 10 is the integral of the rate of growth function r(t) from t=3 to t=10. This is represented by the integral expression ∫310r(t)dt.
Antiderivative of r(t): The integral of r(t)=t2+2t from t=3 to t=10 will give us the total number of people added to the population during this time. We can calculate this integral using the fundamental theorem of calculus.
Evaluate upper limit: First, we find the antiderivative of r(t). The antiderivative of t2 is (1/3)t3, and the antiderivative of 2t is t2. So the antiderivative of r(t) is (1/3)t3+t2.
Evaluate lower limit: Next, we evaluate the antiderivative at the upper limit of integration, which is t=10. Plugging in 10, we get (1/3)(10)3+(10)2=(1/3)(1000)+100=333.33+100=433.33.
Subtract values: Then, we evaluate the antiderivative at the lower limit of integration, which is t=3. Plugging in 3, we get (1/3)(3)3+(3)2=(1/3)(27)+9=9+9=18.
Final population growth: Now, we subtract the value of the antiderivative at t=3 from the value at t=10 to find the total population growth between these years. 433.33−18=415.33.
Correct expression: Therefore, the population grew by 415.33 people from year 3 to year 10. The correct expression to use for solving this problem is (B) ∫310r(t)dt.
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