Answer
\( f(5) = 182.25 \)
Solution
Given that \( f(x) \) is an exponential function of the form \( y = ab^x \), where \( f(4) = 16 \) and \( f(4.5) = 54 \), we need to find the value of \( f(5) \) to the nearest hundredth.
To find the value of \( f(5) \), we first need to determine the values of \( a \) and \( b \) using the given information.
From the given information, we have:
1. \( f(4) = 16 \)
2. \( f(4.5) = 54 \)
We can use these two equations to solve for \( a \) and \( b \).
Let's start by using the first equation \( f(4) = 16 \) to find the value of \( a \):
\[ 16 = ab^4 \]
Now, let's use the second equation \( f(4.5) = 54 \) to find the value of \( b \):
\[ 54 = ab^{4.5} \]
We can solve these two equations simultaneously to find the values of \( a \) and \( b \).
Let's solve these equations to find the values of \( a \) and \( b \) and then use them to find the value of \( f(5) \).
Solve the system of equations by following steps:
- step0: Solve using the substitution method:
\(\left\{ \begin{array}{l}16=ab^{4}\\54=ab^{4.5}\end{array}\right.\)
- step1: Calculate:
\(\left\{ \begin{array}{l}16=ab^{4}\\54=ab^{\frac{9}{2}}\end{array}\right.\)
- step2: Solve the equation:
\(\left\{ \begin{array}{l}a=\frac{16}{b^{4}}\\54=ab^{\frac{9}{2}}\end{array}\right.\)
- step3: Substitute the value of \(a:\)
\(54=\frac{16}{b^{4}}\times b^{\frac{9}{2}}\)
- step4: Reduce the fraction:
\(54=16b^{\frac{1}{2}}\)
- step5: Swap the sides:
\(16b^{\frac{1}{2}}=54\)
- step6: Divide both sides:
\(\frac{16b^{\frac{1}{2}}}{16}=\frac{54}{16}\)
- step7: Divide the numbers:
\(b^{\frac{1}{2}}=\frac{27}{8}\)
- step8: Raise both sides to the \(2\)-th power\(:\)
\(\left(b^{\frac{1}{2}}\right)^{2}=\left(\frac{27}{8}\right)^{2}\)
- step9: Evaluate the power:
\(b=\frac{729}{64}\)
- step10: Substitute the value of \(b:\)
\(a=\frac{16}{\left(\frac{729}{64}\right)^{4}}\)
- step11: Simplify:
\(a=\frac{2^{28}}{729^{4}}\)
- step12: Calculate:
\(\left\{ \begin{array}{l}a=\frac{2^{28}}{729^{4}}\\b=\frac{729}{64}\end{array}\right.\)
- step13: Check the solution:
\(\left\{ \begin{array}{l}a=\frac{2^{28}}{729^{4}}\\b=\frac{729}{64}\end{array}\right.\)
- step14: Rewrite:
\(\left(a,b\right) = \left(\frac{2^{28}}{729^{4}},\frac{729}{64}\right)\)
The solution to the system of equations is \( a = \frac{2^{28}}{729^{4}} \) and \( b = \frac{729}{64} \).
Now that we have the values of \( a \) and \( b \), we can find the value of \( f(5) \) using the exponential function \( f(x) = ab^x \).
Substitute the values of \( a \) and \( b \) into the function to find \( f(5) \):
\[ f(5) = \frac{2^{28}}{729^{4}} \times \left(\frac{729}{64}\right)^5 \]
Let's calculate the value of \( f(5) \) to the nearest hundredth.
Calculate the value by following steps:
- step0: Calculate:
\(\frac{2^{28}}{729^{4}}\times \left(\frac{729}{64}\right)^{5}\)
- step1: Evaluate the power:
\(\frac{2^{28}}{729^{4}}\times \frac{729^{5}}{64^{5}}\)
- step2: Rewrite the expression:
\(\frac{2^{28}}{729^{4}}\times \frac{729^{5}}{2^{30}}\)
- step3: Reduce the numbers:
\(1\times \frac{729}{2^{2}}\)
- step4: Multiply:
\(\frac{729}{2^{2}}\)
- step5: Evaluate the power:
\(\frac{729}{4}\)
The value of \( f(5) \) to the nearest hundredth is 182.25.
Reviewed and approved by the UpStudy tutoring team
Explain
Simplify this solution