Account balance: The balance B, in dollars, of your checking account is a function of t, the number of months since the account was opened. The balance is given by the formula a. Use your calculator...

Account balance: The balance B, in dollars, of your checking account is a function of t, the number of months since the account was opened. The balance is given by the formula

a. Use your calculator to make a graph of B versus t covering the first 15 months.

b. Calculate dB dt at t = 8.

c. Explain what the number you calculated in part b means in practical terms.