document.write( "Question 910598: write an equation of perpendicular line through (1,-5) perpendicular to y=1/8x+2 \n" ); document.write( "
Algebra.Com's Answer #552569 by MathLover1(20850)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: Finding the Equation of a Line Parallel or Perpendicular to a Given Line

\n" ); document.write( "
\n" ); document.write( " Remember, any two perpendicular lines are negative reciprocals of each other. So if you're given the slope of \"1%2F8\", you can find the perpendicular slope by this formula:
\n" ); document.write( "
\n" ); document.write( " \"m%5Bp%5D=-1%2Fm\" where \"m%5Bp%5D\" is the perpendicular slope
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m%5Bp%5D=-1%2F%281%2F8%29\" So plug in the given slope to find the perpendicular slope
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m%5Bp%5D=%28-1%2F1%29%288%2F1%29\" When you divide fractions, you multiply the first fraction (which is really \"1%2F1\") by the reciprocal of the second
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"m%5Bp%5D=-8%2F1\" Multiply the fractions.
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So the perpendicular slope is \"-8\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So now we know the slope of the unknown line is \"-8\" (its the negative reciprocal of \"1%2F8\" from the line \"y=%281%2F8%29%2Ax%2B2\").\n" ); document.write( "Also since the unknown line goes through (1,-5), we can find the equation by plugging in this info into the point-slope formula
\n" ); document.write( "
\n" ); document.write( " Point-Slope Formula:
\n" ); document.write( "
\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 the given point
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B5=-8%2A%28x-1%29\" Plug in \"m=-8\", \"x%5B1%5D=1\", and \"y%5B1%5D=-5\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B5=-8%2Ax%2B%288%29%281%29\" Distribute \"-8\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y%2B5=-8%2Ax%2B8\" Multiply
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=-8%2Ax%2B8-5\"Subtract \"-5\" from both sides to isolate y
\n" ); document.write( "
\n" ); document.write( " \"y=-8%2Ax%2B3\" Combine like terms
\n" ); document.write( "
\n" ); document.write( " So the equation of the line that is perpendicular to \"y=%281%2F8%29%2Ax%2B2\" and goes through (\"1\",\"-5\") is \"y=-8%2Ax%2B3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So here are the graphs of the equations \"y=%281%2F8%29%2Ax%2B2\" and \"y=-8%2Ax%2B3\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " graph of the given equation \"y=%281%2F8%29%2Ax%2B2\" (red) and graph of the line \"y=-8%2Ax%2B3\"(green) that is perpendicular to the given graph and goes through (\"1\",\"-5\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" );