Math Problem Statement

What is the range of the following function in interval notation: f(x)=-4|2x+6|-7

Solution

To find the range of the function f(x)=42x+67f(x) = -4|2x + 6| - 7, we proceed step by step:

Step 1: Analyze the structure of the function.

The function consists of a constant multiple of an absolute value function, with a vertical shift.

  • The term 2x+6|2x + 6| represents the absolute value of a linear expression. Since absolute values are always non-negative, we know that: 2x+60|2x + 6| \geq 0
  • When multiplied by -4, this changes the direction of the inequality: 42x+60-4|2x + 6| \leq 0
  • The smallest value that 42x+6-4|2x + 6| can take is 00 when 2x+6=0|2x + 6| = 0, which happens when x=3x = -3.

Step 2: Shift the function by subtracting 7.

  • Now we subtract 7 from the expression: f(x)=42x+67f(x) = -4|2x + 6| - 7 This shifts the entire function downward by 7 units. Therefore: f(x)7f(x) \leq -7 The maximum value of the function occurs when 2x+6=0|2x + 6| = 0, which happens at x=3x = -3. At this point: f(3)=4(0)7=7f(-3) = -4(0) - 7 = -7

  • As xx moves away from 3-3, 2x+6|2x + 6| increases, and thus f(x)f(x) becomes more negative. Hence, the function decreases without bound.

Step 3: Determine the range.

  • The function reaches its maximum value of 7-7 at x=3x = -3, and it decreases toward -\infty as xx moves further away from 3-3.

Thus, the range of the function in interval notation is: (,7]\boxed{(-\infty, -7]}

Do you want more details or have any questions?

Here are 5 related questions:

  1. How do we find the domain of absolute value functions?
  2. What is the effect of multiplying an absolute value function by a negative number?
  3. How does vertical translation affect the range of a function?
  4. How would the range change if the constant in the function were positive instead of negative?
  5. What happens to the graph of f(x)f(x) if the 7-7 were replaced with another constant?

Tip: When dealing with absolute value functions, always first analyze the behavior of the function inside the absolute value before considering transformations like scaling and translations.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Absolute Value Functions
Vertical Shifts
Multiplying by Negative Numbers
Function Range

Formulas

f(x) = -4|2x + 6| - 7

Theorems

Range of Absolute Value Functions

Suitable Grade Level

Grades 10-12