Equation of a Line in Point-Slope, Slope-Intercept, General FormDate: 8/2/96 at 1:58:36 From: Alfred T Chu Subject: Finding the Equation of a Line Hello Dr. Math, How do I find an equation of the line L that contains the point (4, -4) and is perpendicular to the line that has the equation 2x-5y+3 = 0? I need the equation in: a. Point-slope form b. Slope-intercept form c. General form I am practicing problems from a math workbook and having problems doing it. Thank you very much for helping me! Sincerely, Alfred Date: 8/2/96 at 13:21:33 From: Doctor Anthony Subject: Re: Finding the Equation of a Line The slope of the line 2x-5y+3 = 0 is found by putting this in the y = mc+c from 5y = 2x+3 so y = (2/5)x + (3/5) so slope is 2/5 A line perpendicular to this will have slope -5/2 The required line therefore has the equation y+4 = -(5/2)(x-4) This is the point slope form 2y + 8 = -5x + 20 2y = -5x + 12 y = -(5/2)x + 6 This is the slope intercept form 5x + 2y - 12 = 0 This is the general form -Doctor Anthony, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994-2013 The Math Forum
http://mathforum.org/dr.math/