Math Problem Statement

Give a rule of the form ​f(x)equals=a Superscript xax to define the exponential function whose graph contains the given point. ​(a)​ (33​,2727​) ​(b)​ (negative 2−2​,3636​) Question content area bottom Part 1 ​(a) The graph of the exponential function ​f(x)equals=3 Superscript x3x passes through the point ​(33​,2727​). ​(Simplify your answer. Use integers or fractions for any numbers in the​ expression.) Part 2 ​(b) The graph of the exponential function ​f(x)equals=enter your response here passes through the point ​(negative 2−2​,3636​). ​(Simplify your answer. Use integers or fractions for any numbers in the​ expression.)

Solution

To define the exponential function f(x)=axf(x) = a^x that passes through the given points, we can use the point (x0,y0)(x_0, y_0) on the graph to find the value of aa. Let's break it down for both parts:

Part 1:

We are given the point (3,27)(3, 27).

The general form of the exponential function is f(x)=axf(x) = a^x. Since f(3)=27f(3) = 27, we can substitute these values into the equation:

f(3)=a3=27f(3) = a^3 = 27

Now, solve for aa:

a3=27a=273=3a^3 = 27 \quad \Rightarrow \quad a = \sqrt[3]{27} = 3

Thus, the exponential function is:

f(x)=3xf(x) = 3^x

Part 2:

We are given the point (2,36)(-2, 36).

Again, using the general form f(x)=axf(x) = a^x and substituting f(2)=36f(-2) = 36, we get:

f(2)=a2=36f(-2) = a^{-2} = 36

Now solve for aa:

a2=361a2=36a2=136a=16a^{-2} = 36 \quad \Rightarrow \quad \frac{1}{a^2} = 36 \quad \Rightarrow \quad a^2 = \frac{1}{36} \quad \Rightarrow \quad a = \frac{1}{6}

Thus, the exponential function is:

f(x)=(16)xf(x) = \left( \frac{1}{6} \right)^x

Final Answers:

  1. f(x)=3xf(x) = 3^x for the point (3,27)(3, 27).
  2. f(x)=(16)xf(x) = \left( \frac{1}{6} \right)^x for the point (2,36)(-2, 36).

Do you want details on how I solved for aa in part (b)? Here are 5 related questions:

  1. What are the characteristics of exponential functions?
  2. How do we determine if a function is exponential from a set of points?
  3. What happens when the base of an exponential function is a fraction?
  4. How can we generalize exponential growth and decay functions?
  5. How do transformations affect the graph of exponential functions?

Tip: For exponential functions, the base aa determines the rate of growth or decay: a>1a > 1 implies growth, while 0<a<10 < a < 1 implies decay.

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Math Problem Analysis

Mathematical Concepts

Exponential Functions
Algebra
Function Graphs

Formulas

f(x) = a^x
a^x = y

Theorems

Exponential Growth and Decay Theorem

Suitable Grade Level

Grades 9-12