MATHEMATICS · Subjective · AP · AP Precalculus · Exponential and Logarithmic Functions · Exponential and Logarithmic Functions
Problem
A student deposits two different sums of money, one in Account A and another in Account B. After each complete year, the balances (in rupees) are modelled by
A(t)=6000(1.06)t,B(t)=7500(0.92)t,
where t is the number of full years that have elapsed.
(i) Identify which account balance shows growth and which shows decay.
(ii) Calculate the balance in each account at the end of 3 years.
(iii) Without performing any further calculation, say whether the graph of A(t) is increasing or decreasing, and whether the graph of B(t) is increasing or decreasing, giving one reason for each answer.