document.write( "Question 144187: Please help me answer this question: \r
\n" ); document.write( "\n" ); document.write( "What is the equation of the line, g(x), that is perpendicular to f(x)=1/2x+2 and passes through (0,2)?
\n" ); document.write( "

Algebra.Com's Answer #104956 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\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%2F2\", 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%2F2%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%282%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=-2%2F1\" Multiply the fractions.
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So the perpendicular slope is \"-2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So now we know the slope of the unknown line is \"-2\" (its the negative reciprocal of \"1%2F2\" from the line \"y=%281%2F2%29%2Ax%2B2\").\n" ); document.write( "Also since the unknown line goes through (0,2), 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-2=-2%2A%28x-0%29\" Plug in \"m=-2\", \"x%5B1%5D=0\", and \"y%5B1%5D=2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y-2=-2%2Ax%2B%282%29%280%29\" Distribute \"-2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y-2=-2%2Ax-0\" Multiply
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"y=-2%2Ax-0%2B2\"Add \"2\" to both sides to isolate y
\n" ); document.write( "
\n" ); document.write( " \"y=-2%2Ax%2B2\" Combine like terms
\n" ); document.write( "
\n" ); document.write( " So the equation of the line that is perpendicular to \"y=%281%2F2%29%2Ax%2B2\" and goes through (\"0\",\"2\") is \"y=-2%2Ax%2B2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So here are the graphs of the equations \"y=%281%2F2%29%2Ax%2B2\" and \"y=-2%2Ax%2B2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " graph of the given equation \"y=%281%2F2%29%2Ax%2B2\" (red) and graph of the line \"y=-2%2Ax%2B2\"(green) that is perpendicular to the given graph and goes through (\"0\",\"2\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" );