Writing Exponential Functions

Instructions: Create the equation of the form [tex]\( y = a(b)^x \)[/tex] for the exponential function described in each real-world problem. Then, use the equation to answer the question.

Haley invested $750 into a mutual fund that paid 3.5% interest each year, compounded annually. Find the value of the mutual fund in 15 years.

What number will you fill in for [tex]\( a \)[/tex] to solve the equation?



Answer :

To solve the problem of finding the value of Haley's mutual fund investment in 15 years, we'll use the following exponential function formula for compound interest:

[tex]\[ A = P(1 + r)^t \][/tex]

where:
- [tex]\(A\)[/tex] is the amount of money accumulated after [tex]\(t\)[/tex] years, including interest.
- [tex]\(P\)[/tex] is the principal amount (the initial amount of money).
- [tex]\(r\)[/tex] is the annual interest rate (decimal).
- [tex]\(t\)[/tex] is the number of years the money is invested.

Step-by-Step Solution:

1. Identify the given values:
- Principal amount ([tex]\(P\)[/tex]): [tex]$750 - Annual interest rate (\(r\)): 3.5% (which is 0.035 in decimal form) - Number of years (\(t\)): 15 2. Substitute these values into the formula: \[ A = 750 \times (1 + 0.035)^{15} \] 3. Compute the expression inside the parenthesis: \[ 1 + 0.035 = 1.035 \] 4. Raise this result to the power of 15: \[ 1.035^{15} \] 5. Multiply this result by the principal amount \(750\): \[ 750 \times 1.035^{15} \approx 1256.51 \] So the value of the mutual fund after 15 years is approximately $[/tex]1256.51.

Therefore, the number you would fill in for [tex]\(a\)[/tex] to solve the equation [tex]\(3 = 8\)[/tex] is outside the scope of this problem since it concerns a different equation. For the given investment problem, the initial principal (a) is [tex]$750. The final answer is approximately $[/tex]1256.51, indicating the value of Haley's mutual fund in 15 years.