document.write( "Question 446237: In the equation of a parabola y = (x-5)^2 + 4, I understand the vertex is (5,4). I don't understand why we take the opposite of what is in the parenthesis with the x. It seems to me we would translate the vertex of the graph left 5 units, not right 5 units. Can someone please help me understand this? Thanks.
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Algebra.Com's Answer #307303 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! In the equation of a parabola y = (x-5)^2 + 4, I understand the vertex is (5,4). I don't understand why we take the opposite of what is in the parenthesis with the x. It seems to me we would translate the vertex of the graph left 5 units, not right 5 units. \n" ); document.write( "----------------- \n" ); document.write( "Try thinking of it this way. \n" ); document.write( "If you had the equation y = x^2+4 \n" ); document.write( "y would be 4 when x is zero. \n" ); document.write( "--------------------------------------- \n" ); document.write( "You have the equation y = (x-5)^2 + 4 \n" ); document.write( "y will be 4 when (x-5) is zero. \n" ); document.write( "That happens when x = 5. \n" ); document.write( "------------------------------------- \n" ); document.write( "What happened before at x = 0 now \n" ); document.write( "happens when x = 5. \n" ); document.write( "The graph has moved 5 to the right. \n" ); document.write( "------------------------------------------- \n" ); document.write( "This is the way I teach the idea. \n" ); document.write( "Think of the x-axis as a time line where \n" ); document.write( "time flows from left to right i.e. 0 seconds, 1 second, ...., 5 seconds etc. \n" ); document.write( "--- \n" ); document.write( "t is some time on the t-axis. \n" ); document.write( "t-5 is 5 seconds later on the t-axis. \n" ); document.write( "\"later\" means to the right. \n" ); document.write( "--- \n" ); document.write( "t+5 would mean 5 seconds earlier. \n" ); document.write( "\"earlier\" means to the left.\r \n" ); document.write( "\n" ); document.write( "=============================== \n" ); document.write( "Hope this helps. \n" ); document.write( "=================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " |