document.write( "Question 325447: Give the equation of the line that is perpendicular to the line y = x+4 and passes through point (0, -1). \n" ); document.write( "
Algebra.Com's Answer #233036 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "We can see that the equation \"y=x%2B4\" has a slope \"m=1\" and a y-intercept \"b=4\".\r
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\n" ); document.write( "\n" ); document.write( "Now to find the slope of the perpendicular line, simply flip the slope \"m=1\" to get \"m=1%2F1\". Now change the sign to get \"m=-1\". So the perpendicular slope is \"m=-1\".\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point slope formula to find the equation of the perpendicular line by plugging in the slope \"m=-1\" and the coordinates of the given point .\r
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\n" ); document.write( "\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" Start with the point slope formula\r
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\n" ); document.write( "\n" ); document.write( "\"y--1=-1%28x-0%29\" Plug in \"m=-1\", \"x%5B1%5D=0\", and \"y%5B1%5D=-1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=-1%28x-0%29\" Rewrite \"y--1\" as \"y%2B1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=-x-1%28-0%29\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B1=-x%2B0\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=-x%2B0-1\" Subtract 1 from both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"y=-x-1\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "So the equation of the line perpendicular to \"y=x%2B4\" that goes through the point is \"y=-x-1\".\r
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\n" ); document.write( "\n" ); document.write( "Here's a graph to visually verify our answer:\r
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\n" ); document.write( "\n" ); document.write( "Graph of the original equation \"y=x%2B4\" (red) and the perpendicular line \"y=-x-1\" (green) through the point .
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