Math Problem Statement

The image describes a mathematical function f(x) = 5x - 7 and asks how many of the following statements are true: (1) f^{-1}(-2) = 1, (2) f^{-1}(0) = 2, (3) f^{-1}(3) = 3, (4) f^{-1}(7) = 4.

Solution

The image describes a mathematical function f(x)=5x7f(x) = 5x - 7 and asks how many of the following statements are true, based on the information provided:

  1. f1(2)=1f^{-1}(-2) = 1
  2. f1(0)=2f^{-1}(0) = 2
  3. f1(3)=3f^{-1}(3) = 3
  4. f1(7)=4f^{-1}(7) = 4

We are dealing with the inverse function f1(x)f^{-1}(x), which means we need to solve for xx in the equation f(x)=yf(x) = y, where yy is given.

Step 1: Determine the inverse function f1(x)f^{-1}(x)

We start with the function f(x)=5x7f(x) = 5x - 7. To find the inverse, follow these steps:

  1. Set y=f(x)=5x7y = f(x) = 5x - 7.
  2. Solve for xx in terms of yy:

y=5x7y = 5x - 7 y+7=5xy + 7 = 5x x=y+75x = \frac{y + 7}{5}

So, the inverse function is:

f1(x)=x+75f^{-1}(x) = \frac{x + 7}{5}

Step 2: Evaluate the statements

  1. f1(2)=1f^{-1}(-2) = 1 f1(2)=2+75=55=1f^{-1}(-2) = \frac{-2 + 7}{5} = \frac{5}{5} = 1 This is true.

  2. f1(0)=2f^{-1}(0) = 2 f1(0)=0+75=75=1.4f^{-1}(0) = \frac{0 + 7}{5} = \frac{7}{5} = 1.4 This is false.

  3. f1(3)=3f^{-1}(3) = 3 f1(3)=3+75=105=2f^{-1}(3) = \frac{3 + 7}{5} = \frac{10}{5} = 2 This is false.

  4. f1(7)=4f^{-1}(7) = 4 f1(7)=7+75=145=2.8f^{-1}(7) = \frac{7 + 7}{5} = \frac{14}{5} = 2.8 This is false.

Conclusion:

Only the first statement is true. Therefore, the correct answer is 1.

Would you like any further details or clarifications?


Here are 5 related questions:

  1. How do you calculate the inverse of a quadratic function?
  2. What are the conditions for a function to have an inverse?
  3. Can every linear function have an inverse? Why or why not?
  4. How would the graph of f(x)=5x7f(x) = 5x - 7 and its inverse look?
  5. How does the process of finding the inverse change for non-linear functions?

Tip: Always verify if a function is one-to-one before attempting to find its inverse.

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Math Problem Analysis

Mathematical Concepts

Inverse functions
Linear equations

Formulas

f(x) = 5x - 7
f^{-1}(x) = (x + 7) / 5

Theorems

Inverse function theorem

Suitable Grade Level

Grades 9-11