Math Problem Statement

If f(x) is an exponential function of the form of y=ab^x where f(1) = 24 and f(8) = 76, then find the value of f(11) to the nearest hundredth.

Solution

Given the exponential function f(x)=abxf(x) = ab^x and the conditions f(1)=24f(1) = 24 and f(8)=76f(8) = 76, we need to find the value of f(11)f(11).

Step 1: Set up the equations using the given points.

  • For x=1x = 1: f(1)=ab1=ab=24(Equation 1)f(1) = ab^1 = ab = 24 \quad \text{(Equation 1)}
  • For x=8x = 8: f(8)=ab8=76(Equation 2)f(8) = ab^8 = 76 \quad \text{(Equation 2)}

Step 2: Solve for bb.

Divide Equation 2 by Equation 1: ab8ab=7624\frac{ab^8}{ab} = \frac{76}{24} b7=7624b^7 = \frac{76}{24} b7=7624=1963.1667b^7 = \frac{76}{24} = \frac{19}{6} \approx 3.1667 b=(196)171.1723b = \left(\frac{19}{6}\right)^{\frac{1}{7}} \approx 1.1723

Step 3: Solve for aa.

Substitute the value of bb into Equation 1: a(1.1723)=24a(1.1723) = 24 a=241.172320.474a = \frac{24}{1.1723} \approx 20.474

Step 4: Find f(11)f(11).

Now, use the values of aa and bb to calculate f(11)f(11): f(11)=ab11=20.474×(1.1723)11f(11) = ab^{11} = 20.474 \times (1.1723)^{11} Calculate (1.1723)11(1.1723)^{11}: (1.1723)112.241(1.1723)^{11} \approx 2.241 Thus, f(11)20.474×2.24145.91f(11) \approx 20.474 \times 2.241 \approx 45.91

So, the value of f(11)f(11) to the nearest hundredth is approximately 45.91.

Would you like more details on any part of this solution or have any questions?

Here are 5 related questions for further exploration:

  1. How does changing the base bb in an exponential function affect its graph?
  2. What would the value of f(x)f(x) be if xx were negative?
  3. How can you determine the value of xx given a specific f(x)f(x) value?
  4. What is the significance of the constant aa in the exponential function y=abxy = ab^x?
  5. Can you derive the formula for the inverse of an exponential function?

Tip: When dealing with exponential functions, it's important to understand the relationship between the base and the rate of growth or decay.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Equations
Logarithms

Formulas

Exponential function formula y = ab^x

Theorems

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Suitable Grade Level

Grades 10-12