Math Problem Statement

Write the equation of a line that passes through the point (-6, 9) and is perpendicular to a line that passes through the points (-2, 1) and (6, 7) in slope-intercept form.

Solution

The question asks you to write the equation of a line that passes through the point (6,9)(-6, 9) and is perpendicular to a line that passes through the points (2,1)(-2, 1) and (6,7)(6, 7). This equation must be in slope-intercept form.

Step-by-step solution:

  1. Find the slope of the given line: The slope of a line passing through two points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is calculated by the formula:

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

    Substituting the given points (2,1)(-2, 1) and (6,7)(6, 7):

    m=716(2)=68=34m = \frac{7 - 1}{6 - (-2)} = \frac{6}{8} = \frac{3}{4}

    So, the slope of the given line is m=34m = \frac{3}{4}.

  2. Find the slope of the perpendicular line: The slope of a line perpendicular to another line is the negative reciprocal of the original slope. If the original slope is mm, the perpendicular slope is 1m-\frac{1}{m}.

    Since the slope of the given line is 34\frac{3}{4}, the slope of the perpendicular line is:

    m=43m_{\perp} = -\frac{4}{3}

  3. Use point-slope form to find the equation: Now, use the point-slope form of a line equation:

    yy1=m(xx1)y - y_1 = m(x - x_1)

    Where m=43m = -\frac{4}{3} and (x1,y1)(x_1, y_1) is (6,9)(-6, 9):

    y9=43(x+6)y - 9 = -\frac{4}{3}(x + 6)

  4. Simplify to slope-intercept form: Distribute the slope:

    y9=43x8y - 9 = -\frac{4}{3}x - 8

    Add 9 to both sides:

    y=43x+1y = -\frac{4}{3}x + 1

Final Equation:

The equation of the line is:

y=43x+1y = -\frac{4}{3}x + 1


Do you want more details on any part of this solution? Here are 5 related questions to extend your understanding:

  1. How do you calculate the slope of a line passing through two points?
  2. What is the significance of the negative reciprocal when finding perpendicular slopes?
  3. Can you explain the point-slope form of a line and its uses?
  4. How would the equation change if the line were parallel instead of perpendicular?
  5. What would the graph of the perpendicular lines look like?

Tip: Always remember that perpendicular lines have slopes that multiply to give 1-1.

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Math Problem Analysis

Mathematical Concepts

Linear Equations
Slopes
Perpendicular Lines
Slope-Intercept Form

Formulas

Slope formula: m = (y2 - y1) / (x2 - x1)
Slope-intercept form: y = mx + b
Negative reciprocal for perpendicular slopes: m1 * m2 = -1

Theorems

Perpendicular line theorem

Suitable Grade Level

Grade 9-11