document.write( "Question 99323: Using the form y=mx+b,find the equation for ;The line thru the orgin that is perpendicular to the line through (-3,0) and(0,- 3) \n" ); document.write( "
Algebra.Com's Answer #72247 by edjones(8007)\"\" \"About 
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"0\",\"-3\") and (\"-3\",\"0\")
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\n" ); document.write( " \"m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\" Start with the slope formula (note: (\"x%5B1%5D\",\"y%5B1%5D\") is the first point (\"0\",\"-3\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"-3\",\"0\"))
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\n" ); document.write( " \"m=%280--3%29%2F%28-3-0%29\" Plug in \"y%5B2%5D=0\",\"y%5B1%5D=-3\",\"x%5B2%5D=-3\",\"x%5B1%5D=0\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+3%2F-3\" Subtract the terms in the numerator \"0--3\" to get \"3\". Subtract the terms in the denominator \"-3-0\" to get \"-3\"
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\n" ); document.write( " \"m=-1\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=-1\"
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\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
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\n" ); document.write( " ------Point-Slope Formula------
\n" ); document.write( " \"y-y%5B1%5D=m%28x-x%5B1%5D%29\" where \"m\" is the slope, and (\"x%5B1%5D\",\"y%5B1%5D\") is one of the given points
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\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
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\n" ); document.write( " \"y--3=%28-1%29%28x-0%29\" Plug in \"m=-1\", \"x%5B1%5D=0\", and \"y%5B1%5D=-3\" (these values are given)
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\n" ); document.write( " \"y%2B3=%28-1%29%28x-0%29\" Rewrite \"y--3\" as \"y%2B3\"
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\n" ); document.write( " \"y%2B3=-x%2B%28-1%29%280%29\" Distribute \"-1\"
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\n" ); document.write( " \"y%2B3=-x%2B0\" Multiply \"-1\" and \"0\" to get \"0%2F1\". Now reduce \"0%2F1\" to get \"0\"
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\n" ); document.write( " \"y=-x%2B0-3\" Subtract \"3\" from both sides to isolate y
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\n" ); document.write( " \"y=-x-3\" Combine like terms \"0\" and \"-3\" to get \"-3\"
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\n" ); document.write( " Answer:
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\n" ); document.write( " So the equation of the line which goes through the points (\"0\",\"-3\") and (\"-3\",\"0\") is:\"y=-x-3\"
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\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=-1\" and the y-intercept is \"b=-3\"
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\n" ); document.write( " Notice if we graph the equation \"y=-x-3\" and plot the points (\"0\",\"-3\") and (\"-3\",\"0\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=-x-3\" through the points (\"0\",\"-3\") and (\"-3\",\"0\")
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\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
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\n" ); document.write( "\n" ); document.write( "y= -x-3 slope=m= -1
\n" ); document.write( "slope of a line perpendicular to any line is its negative reciprocal: \"m=+-1%2Fm%5B1%5D=+-1%2F-1=+1\"
\n" ); document.write( "the origin is point (0,0)
\n" ); document.write( "y-y[1]=m(x-x[1])
\n" ); document.write( "y-0=1(x-0)
\n" ); document.write( "so our equation for the in through the origin perpendicular to our 1st line is y=x
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\n" ); document.write( "\"graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C-x-3%2Cx%29\"
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