document.write( "Question 1078174: Can you please help me to sketch the graph, given is y=ax^2+bx+c where a<0 ; b<0 ; c<0 and ax^2+bx+c has only one solution. \n" ); document.write( "
Algebra.Com's Answer #692642 by KMST(5328)\"\" \"About 
You can put this solution on YOUR website!
You mean that \"ax%5E2%2Bbx%2Bc=0\" has only one solution.
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\n" ); document.write( "If a<0 the graph opens down (like a frowny mouth),
\n" ); document.write( "and goes down without a bottom on the left end and on the right end,
\n" ); document.write( "like
\n" ); document.write( "\"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.3%28x%2B0.2%29%5E2%29\" , or \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.18%2C0.2%2C-1.3%28x-0.2%29%5E2%2B0.1%29\" , or \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.3%28x-0.2%29%5E2-0.1%29\" .
\n" ); document.write( "That means there are at least some points below the x-axis.
\n" ); document.write( "In this specific case, because b<0 and c<0 too,
\n" ); document.write( "it is also obvious that for \"x=1\" \"ax%5E2%2Bbx%2Bc=a%2Bb%2Bc%3C0\" .
\n" ); document.write( "If there were also some points above the x-axis
\n" ); document.write( "the graph would have to cross the x-axis twice,
\n" ); document.write( "but the fact that \"ax%5E2%2Bbx%2Bc=0\" has only one solution
\n" ); document.write( "means that it just touches it once and does not cross it,
\n" ); document.write( "like \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.3%28x%2B0.2%29%5E2%29\" , or \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.1%28x-0.4%29%5E2%29\" , or \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-x%5E2%29\" .
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\n" ); document.write( "I do not know if it was your teachers intention,
\n" ); document.write( "but the point where the graph touches the x- axis
\n" ); document.write( "must have \"x=-b%2F2a\" .
\n" ); document.write( "Did you learn in class that the vertex of the graph
\n" ); document.write( "is at \"x=-b%2F2a\" ?
\n" ); document.write( "If both (a and b) are negative,
\n" ); document.write( "that is \"x=-b%2F2a\" ,
\n" ); document.write( "so the graph can look like \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.3%28x%2B0.2%29%5E2%29\" , or \"graph%28200%2C200%2C-0.9%2C0.9%2C-0.19%2C0.1%2C-1.1%28x%2B0.4%29%5E2%29\" ,
\n" ); document.write( "touching the x-axis to the left of the origin.
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