we are given the following formula for the balance of a bank account:
![f(t)=10e^(0.07t)](https://img.qammunity.org/2023/formulas/mathematics/college/7um2wu0mbyhl56tjbipafd37iuulbfatfi.png)
a. The opening balance is given when the value of the time "t" is zero, that is t = 0:
![\begin{gathered} f(0)=10e^(0.07(0)) \\ f(0)=10 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zj6f724qfhu4ygopi1gkrna8aqg2h1jywg.png)
Therefore, the initial balance is 10.
b. To determine when the balance reaches 1000000 we need to replace f(t) = 1000000 and solve for "t":
![1000000=e^(0.07t)](https://img.qammunity.org/2023/formulas/mathematics/college/zrpzqblzuo6w5x6g2kaaqe9equfx07fzev.png)
Taking natural logarithm on both sides:
![\ln 1000000=0.07t](https://img.qammunity.org/2023/formulas/mathematics/college/xbh7ga7tvpqykru1vt6hlgp6j1i0wq8lt2.png)
Dividing both sides by 0.07:
![(1)/(0.07)\ln 1000000=t](https://img.qammunity.org/2023/formulas/mathematics/college/8dvlgpyduotiiem3kzvsfjjahclp0h4bnf.png)
Solving the operation:
![197.4=t](https://img.qammunity.org/2023/formulas/mathematics/college/fxotjzxwzlkxgzqw64ethhhhxadwbf2d86.png)
Therefore, the balance will be 1000000 in 197.4 years.