Math Problem Statement

If f, of, xf(x) is an exponential function of the form of y, equals, a, b, to the power xy=ab x where f, of, 0, point, 5, equals, 16f(0.5)=16 and f, of, 7, equals, 38f(7)=38, then find the value of f, of, 1f(1), to the nearest hundredth.

Solution

We are given that f(x)f(x) is an exponential function of the form:

f(x)=abxf(x) = ab^x

where f(0.5)=16f(0.5) = 16 and f(7)=38f(7) = 38. We need to find f(1)f(1).

Step 1: Express the function using the given form

The general form of the exponential function is:

f(x)=abxf(x) = ab^x

We can use the two known points f(0.5)=16f(0.5) = 16 and f(7)=38f(7) = 38 to form two equations.

  1. At x=0.5x = 0.5, we have: f(0.5)=ab0.5=16f(0.5) = ab^{0.5} = 16
  2. At x=7x = 7, we have: f(7)=ab7=38f(7) = ab^7 = 38

Step 2: Solve for aa and bb

We now have two equations:

  1. ab0.5=16ab^{0.5} = 16
  2. ab7=38ab^7 = 38

To eliminate aa, divide the second equation by the first equation:

ab7ab0.5=3816\frac{ab^7}{ab^{0.5}} = \frac{38}{16}

Simplifying:

b70.5=3816=2.375b^{7 - 0.5} = \frac{38}{16} = 2.375

This gives:

b6.5=2.375b^{6.5} = 2.375

To solve for bb, take the 6.5th root of both sides:

b=(2.375)16.51.138b = \left( 2.375 \right)^{\frac{1}{6.5}} \approx 1.138

Step 3: Solve for aa

Now that we have b1.138b \approx 1.138, substitute it back into the first equation:

ab0.5=16ab^{0.5} = 16

a×1.1380.5=16a \times 1.138^{0.5} = 16

Simplifying 1.1380.51.0671.138^{0.5} \approx 1.067, we get:

a×1.067=16a \times 1.067 = 16

Solving for aa:

a161.06715.0a \approx \frac{16}{1.067} \approx 15.0

Step 4: Find f(1)f(1)

Now that we have a15.0a \approx 15.0 and b1.138b \approx 1.138, substitute into the function f(x)=abxf(x) = ab^x to find f(1)f(1):

f(1)=15.0×1.1381=15.0×1.13817.07f(1) = 15.0 \times 1.138^1 = 15.0 \times 1.138 \approx 17.07

Final Answer:

The value of f(1)f(1) to the nearest hundredth is:

f(1)17.07f(1) \approx 17.07

Would you like more details or have any questions?

Here are 5 related questions:

  1. What would happen if f(x)f(x) were a linear function instead of exponential?
  2. How can the rate of growth of an exponential function be interpreted from bb?
  3. What if we knew f(x)f(x) at three points? How would that affect the process?
  4. Can you find the derivative of f(x)=abxf(x) = ab^x with respect to xx?
  5. How does the base bb relate to exponential growth or decay?

Tip: When solving for unknown parameters in exponential functions, using logarithms can help simplify the calculations involving powers.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Solving Systems of Equations

Formulas

f(x) = ab^x
Exponential equation solving via division and roots

Theorems

Exponent Laws

Suitable Grade Level

Grades 9-12