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Homework Help: Linear lines

  1. Jul 18, 2008 #1
    1. The problem statement, all variables and given/known data

    Find the equation of a straight line which passes through the point (2,3) and is inclined at 30 Celsius to the positive direction of the x-axis.

    3. The attempt at a solution
    i have no idea how to to this question as i was away for a week of school >< and my teacher gave my catch up worksheets. im falling behind class. so need help

    1. The problem statement, all variables and given/known data
    find the angle between the straight line 3x-2y=4 and the line joining the points (-2,-1) and (4,1)

    please guide me step by step

  2. jcsd
  3. Jul 18, 2008 #2


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    Homework Helper

    What you need for the first one is a point on the line (which you were given) and the gradient.
    This will help you to get the gradient:

    Tan(angle the line makes with the +ve x-axis)=gradient of the line.

    EDIT: I think you mean 30 degrees and not celsius as that implies a temperature.
    Last edited: Jul 18, 2008
  4. Jul 19, 2008 #3
    so y=mx+c
    Tan(30degrees) is m =0.56
    so y=0.56x+c

    find c, sub (2,3)

    y=0.56x+1.85 ?
  5. Jul 19, 2008 #4


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    Science Advisor

    (0.56)(2)+ 1.85= 1.12+ 1.85= 2.97, not 3. Did you mean tan(30)= 0.58?
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