document.write( "Question 363181: How do you graph absolute value functions? \n" ); document.write( "
Algebra.Com's Answer #258957 by Edwin McCravy(20056)![]() ![]() You can put this solution on YOUR website! y = 2|3x + 6| - 4\r \n" ); document.write( "\n" ); document.write( "Finding the vertex:\r \n" ); document.write( "\n" ); document.write( "1. Set what's between the absolute value bars = 0\r \n" ); document.write( "\n" ); document.write( "3x + 6 = 0 \n" ); document.write( " 3x = -6 \n" ); document.write( " x = -2\r \n" ); document.write( "\n" ); document.write( "That's the x-coordinate of the vertex.\r \n" ); document.write( "\n" ); document.write( "2. Substitute that in the equation to find the y-coordinate \n" ); document.write( " of the vertex:\r \n" ); document.write( "\n" ); document.write( " y = 2|3(-2)+6| - 4 \n" ); document.write( " y = 2|-6+6| - 4 \n" ); document.write( " y = 2(0) - 4 \n" ); document.write( " y = -4\r \n" ); document.write( "\n" ); document.write( "(Shortcut for this step: the y-coordinate of the vertex is \n" ); document.write( "just the number that's added to the absolute value term, in this \n" ); document.write( "case -4, because when you substitute the x-coordinate the \n" ); document.write( "absolute value term will always be 0)\r \n" ); document.write( "\n" ); document.write( "3. The vertex is (-2,-4)\r \n" ); document.write( "\n" ); document.write( "Plot that:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4. Find one other point, say the y-intercept, so let x=0,\r \n" ); document.write( "\n" ); document.write( "y = 2|3(0) + 6| - 4 \n" ); document.write( "y = 2|0 + 6| - 4 \n" ); document.write( "y = 2|6| - 4 \n" ); document.write( "y = 2(6) - 4 \n" ); document.write( "y = 12 - 4 \n" ); document.write( "y = 8 \n" ); document.write( " \n" ); document.write( "5. Plot the y-intercept (0,8) \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "6. Draw a line through that point stopping at the vertex (-2,-4)\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "7. draw another line to make a symmetrical V-shaped graph, with vertex (-2,-4):\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "That's it!\r \n" ); document.write( "\n" ); document.write( "Edwin \n" ); document.write( " |