document.write( "Question 969034: To edwin. Thanks. I really understand it but i i thinks there is something missing here. You said in the last paragraph that \"So that can only be where the y-axis has positive numbers
\n" ); document.write( "marked on it, which is above the x-axis.\"What is after \"so that?\" is there something missing? \n" ); document.write( "
Algebra.Com's Answer #592055 by Edwin McCravy(20060)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "Maybe you didn't understand that all four of these statements:\r\n" );
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document.write( "1. y is greater than zero\r\n" );
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document.write( "2. y > 0\r\n" );
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document.write( "3. y is positive\r\n" );
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document.write( "4. y is above the x-axis\r\n" );
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document.write( "all say EXACTLY the same thing.\r\n" );
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document.write( "So y can only be greater than zero where the y-axis has positive \r\n" );
document.write( "numbers marked on it.  That's because if y were below the x axis,\r\n" );
document.write( "that is where the y-axis has negative numbers marked on it.\r\n" );
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document.write( "Maybe you didn't unserstand that when we say \"y > 0\" we mean that\r\n" );
document.write( "the points on the graph of y = ax^2+bx+c > 0 have all their y-coordinates\r\n" );
document.write( "positive, and the only points which have their y-coordinates positive\r\n" );
document.write( "are the points above the x-axis where the numbers marked on the y-axis \r\n" );
document.write( "are all positive.\r\n" );
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document.write( "Below is a typical graph of y = ax^2+bx+c > 0.  Notice that the whole graph \r\n" );
document.write( "is ABOVE the x-axis. Look at each point that I have marked on it.  Each point \r\n" );
document.write( "has an x-coordinate and a y-coordinate. The x-coordinate of the point \r\n" );
document.write( "(-4,6) is -4 and the y-coordinate is +6.  The x-coordinate of the point\r\n" );
document.write( "(2,3) is 2 and the y-coordinate is +3.  \r\n" );
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document.write( "Notice that the y-coordinate of every point on that graph is a POSITIVE\r\n" );
document.write( "number. That is it is GREATER than 0.  \r\n" );
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document.write( "Even though some of the x-coordinates are negative and some are positive,\r\n" );
document.write( "and one is 0, that cannot be said about the y-coordinates of those \r\n" );
document.write( "points. The y-coordinates of the points on that graph are all positive and\r\n" );
document.write( "therefore they are all greater than 0.  \" > 0\" means \"greater than 0\".\r\n" );
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document.write( "That's because they are ABOVE the x-axis.  Again, \"positive\" and \"greater \r\n" );
document.write( "than 0\" both mean exactly the same thing.\r\n" );
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document.write( "Edwin
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