Math Problem Statement

Which functions have the same x-intercept as f(x)? Select all that apply.

Solution

To solve this problem, let's determine the x-intercept of the function f(x)f(x) and compare it to the other given functions.


Step 1: Find the x-intercept of f(x)f(x)

The x-intercept occurs when f(x)=0f(x) = 0. Using the table, we see:

  • For x=1x = 1, f(x)=1f(x) = 1, and for x=5x = 5, f(x)=1f(x) = -1.

Using these points, calculate the slope of f(x)f(x): slope=m=f(5)f(1)51=1151=24=12.\text{slope} = m = \frac{f(5) - f(1)}{5 - 1} = \frac{-1 - 1}{5 - 1} = \frac{-2}{4} = -\frac{1}{2}.

Now, the equation of f(x)f(x) can be written as: f(x)=12x+b.f(x) = -\frac{1}{2}x + b.

To find bb, use the point (1,1)(1, 1): 1=12(1)+b    b=1+12=32.1 = -\frac{1}{2}(1) + b \implies b = 1 + \frac{1}{2} = \frac{3}{2}.

Thus, the equation of f(x)f(x) is: f(x)=12x+32.f(x) = -\frac{1}{2}x + \frac{3}{2}.

Now solve for the x-intercept by setting f(x)=0f(x) = 0: 0=12x+32    12x=32    x=3.0 = -\frac{1}{2}x + \frac{3}{2} \implies \frac{1}{2}x = \frac{3}{2} \implies x = 3.

So, the x-intercept of f(x)f(x) is x=3x = 3.


Step 2: Check the x-intercept of the other functions

  1. For g(x)=2x+5g(x) = -2x + 5: Set g(x)=0g(x) = 0: 0=2x+5    2x=5    x=52.0 = -2x + 5 \implies 2x = 5 \implies x = \frac{5}{2}. The x-intercept is not 33, so g(x)g(x) is incorrect.

  2. For h(x)=(x3)2h(x) = (x - 3)^2: Set h(x)=0h(x) = 0: (x3)2=0    x3=0    x=3.(x - 3)^2 = 0 \implies x - 3 = 0 \implies x = 3. The x-intercept matches f(x)f(x), so h(x)h(x) is correct.

  3. For k(x)=(x+3)2+1k(x) = (x + 3)^2 + 1: Set k(x)=0k(x) = 0: (x+3)2+1=0.(x + 3)^2 + 1 = 0. This equation has no real solutions because (x+3)20(x + 3)^2 \geq 0 and adding 1 makes it always positive. So, k(x)k(x) has no x-intercept and is incorrect.

  4. For m(x)=2x6m(x) = 2x - 6: Set m(x)=0m(x) = 0: 0=2x6    2x=6    x=3.0 = 2x - 6 \implies 2x = 6 \implies x = 3. The x-intercept matches f(x)f(x), so m(x)m(x) is correct.


Final Answer:

The functions that have the same x-intercept as f(x)f(x) are: h(x) and m(x).\boxed{h(x) \text{ and } m(x)}.

Let me know if you would like a deeper explanation or have any questions!


Related Questions:

  1. How do you determine the slope of a linear function from a table?
  2. What is the geometric interpretation of an x-intercept?
  3. How do you solve quadratic equations to find their roots?
  4. Why does k(x)=(x+3)2+1k(x) = (x + 3)^2 + 1 have no real x-intercept?
  5. Can a quadratic function have two x-intercepts? If so, under what conditions?

Tip:

Always verify the x-intercept of a function by substituting y=0y = 0 into its equation!

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Math Problem Analysis

Mathematical Concepts

Linear Functions
X-Intercept
Equation Solving

Formulas

Slope formula
Linear equation in slope-intercept form: y = mx + b

Theorems

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Suitable Grade Level

Grades 8-10