document.write( "Question 1157111: A line L1 passes through point[1,2]and has a gradient of 5.Another line L2 is perpendicular to L1 and meets it at Point x=4 .find the equation of L2 in the form y=mx+c \n" ); document.write( "

Algebra.Com's Answer #853773 by ikleyn(53742) $\"\"$ $\"About$

You can put this solution on YOUR website!
A line L1 passes through point[1,2]and has a gradient of 5. Another line L2 is perpendicular to L1
\n" ); document.write( "and meets it at Point x = 4. Find the equation of L2 in the form y = mx + c
\n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~~~~~~\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "        The solution by @mananth in his post is incorrect.\r
\n" ); document.write( "\n" ); document.write( "        He mistakenly assumed that line L2 passes through point (4,0),\r
\n" ); document.write( "\n" ); document.write( "        but the problem states something totally different, instead.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "        See below my correct solution.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "

\r\n" );
document.write( "Line L1: y - 2 = 5*(x-1)\r\n" );
document.write( "\r\n" );
document.write( "         y = 5x - 5 + 2 = 5x - 3.    (1)\r\n" );
document.write( "\r\n" );
document.write( "         Slope of L1 is 5.\r\n" );
document.write( "\r\n" );
document.write( "         Hence, slope L2 is -1/5.\r\n" );
document.write( "\r\n" );
document.write( "         L2 meets L1 at point x = 4,  where  y = 5*4 - 3 = 17,  according to equation (1).\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " Thus, L2 has the slope -1/5 and passes through point (4,17)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Hence, an equation for L2 is\r\n" );
document.write( "\r\n" );
document.write( "    y - 17 = ,\r\n" );
document.write( "\r\n" );
document.write( "or\r\n" );
document.write( "\r\n" );
document.write( "    y - 17 =  + ,\r\n" );
document.write( "\r\n" );
document.write( "    y =  + 17.      <<<---===  ANSWER\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "Solved correctly.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );