Math Problem Statement

The function f is defined by f(x) = a^x + b, where a and b are constants. In the xy-plane, the graph of y = f(x) has an x-intercept at (2, 0) and a y-intercept at (0, -323). What is the value of b?

Solution

To solve this problem, let's analyze the given information and use it to determine the value of bb.

Given:

  • The function f(x)=ax+bf(x) = a^x + b, where aa and bb are constants.
  • f(x)f(x) has an x-intercept at (2,0)(2, 0):
    • This means that when x=2x = 2, f(2)=0f(2) = 0.
  • f(x)f(x) has a y-intercept at (0,323)(0, -323):
    • This means that when x=0x = 0, f(0)=323f(0) = -323.

Step-by-Step Solution:

  1. Use the y-intercept condition:

    • At x=0x = 0: f(0)=a0+b=323f(0) = a^0 + b = -323
    • Since a0=1a^0 = 1: 1+b=3231 + b = -323 b=3231=324b = -323 - 1 = -324
  2. Verify using the x-intercept condition:

    • At x=2x = 2: f(2)=a2+b=0f(2) = a^2 + b = 0
    • Substitute b=324b = -324: a2324=0a^2 - 324 = 0 a2=324a^2 = 324 a=±18a = \pm 18

Final Answer:

b=324\boxed{b = -324}

Would you like a further breakdown of the calculations or the reasoning? Here are some related questions for further practice:

  1. If f(x)=ax+bf(x) = a^x + b and a=2a = 2, find the x-intercept when b=8b = -8.
  2. Determine the y-intercept of the function f(x)=5x10f(x) = 5^x - 10.
  3. How does changing the value of bb affect the graph of f(x)=ax+bf(x) = a^x + b?
  4. Find the derivative of f(x)=ax+bf(x) = a^x + b with respect to xx.
  5. If the x-intercept of f(x)=ax+bf(x) = a^x + b is at (3,0)(3, 0), what is the relationship between aa and bb?

Tip: When finding intercepts, remember that the x-intercept occurs where f(x)=0f(x) = 0 and the y-intercept occurs where x=0x = 0.

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Math Problem Analysis

Mathematical Concepts

Algebra
Exponential Functions
Intercepts

Formulas

f(x) = a^x + b
x-intercept: f(x) = 0
y-intercept: f(0) = b

Theorems

Properties of exponential functions
Intercept theorem

Suitable Grade Level

Grades 10-12