Math Problem Statement

if f(x) is a linear function, f(-5)=0 and f(2)=1, find an equation for f(x)

Solution

Given that f(x)f(x) is a linear function, its equation can be written in the form:

f(x)=mx+bf(x) = mx + b

where mm is the slope and bb is the y-intercept.

Step 1: Find the slope (mm)

The slope of a linear function is given by the formula:

m=y2y1x2x1m = \frac{y_2 - y_1}{x_2 - x_1}

We are given two points: (5,0)(-5, 0) and (2,1)(2, 1). Substituting these values into the slope formula:

m=102(5)=17m = \frac{1 - 0}{2 - (-5)} = \frac{1}{7}

So, the slope m=17m = \frac{1}{7}.

Step 2: Find the y-intercept (bb)

Now that we know the slope, we can use one of the given points to find the y-intercept bb. Let's use the point (2,1)(2, 1).

Substitute m=17m = \frac{1}{7}, x=2x = 2, and f(x)=1f(x) = 1 into the equation f(x)=mx+bf(x) = mx + b:

1=17(2)+b1 = \frac{1}{7}(2) + b

1=27+b1 = \frac{2}{7} + b

Now, solve for bb:

b=127=7727=57b = 1 - \frac{2}{7} = \frac{7}{7} - \frac{2}{7} = \frac{5}{7}

Step 3: Write the equation of the function

Now that we have both mm and bb, the equation for f(x)f(x) is:

f(x)=17x+57f(x) = \frac{1}{7}x + \frac{5}{7}

Would you like further details or clarification?

Here are 5 related questions for further exploration:

  1. How would the equation change if one of the points were different?
  2. Can you express this function in terms of another point-slope form?
  3. What does the graph of this function look like?
  4. How do you find the x-intercept of this function?
  5. How would you calculate the slope if the function were non-linear?

Tip: For any linear function, the slope represents the rate of change between two points.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Linear Functions

Formulas

Linear equation formula f(x) = mx + b
Slope formula m = (y2 - y1) / (x2 - x1)

Theorems

Slope-Intercept Form

Suitable Grade Level

Grades 7-9