Consider the following problem:The number of people in Bernardo's social network is increasing at a rate of r(t)=−2(t−3)2+23 people per month (where t is the time in months since Bernardo set up the network). At time t=4 months, Bernardo had 80 people in his social network. How many people were in Bernardo's social network at the end of the 6th month?Which expression can we use to solve the problem?Choose 1 answer:(A) r(6)(B) 80+∫46r(t)dt(C) ∫46r(t)dt(D) ∫06r(t)dt
Q. Consider the following problem:The number of people in Bernardo's social network is increasing at a rate of r(t)=−2(t−3)2+23 people per month (where t is the time in months since Bernardo set up the network). At time t=4 months, Bernardo had 80 people in his social network. How many people were in Bernardo's social network at the end of the 6th month?Which expression can we use to solve the problem?Choose 1 answer:(A) r(6)(B) 80+∫46r(t)dt(C) ∫46r(t)dt(D) ∫06r(t)dt
Understand the problem: Understand the problem.We are given a rate of change of the number of people in Bernardo's social network, r(t), and the number of people in the network at t=4 months. We need to find the number of people at t=6 months.
Determine correct expression: Determine the correct expression to use.To find the number of people at the end of the 6th month, we need to add the number of people who joined the network from month 4 to month 6 to the number of people already in the network at month 4.
Analyze given expressions: Analyze the given expressions.(A) r(6) would give us the rate of change at the 6th month, not the total number of people.(B) 80+∫46r(t)dt would give us the initial number of people at month 4 plus the total number of people who joined from month 4 to month 6.(C) ∫46r(t)dt would give us only the total number of people who joined from month 4 to month 6, without considering the initial number of people.(D) ∫06r(t)dt would give us the total number of people who joined from month 6th0 to month 6, which is not what we need since we are starting from month 4.
Choose correct expression: Choose the correct expression.The correct expression to use is (B)80+∫46r(t)dt because it accounts for both the initial number of people and the number of people who joined the network from month 4 to month 6.
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