document.write( "Question 194728: How do you find the vertex of y=x^2+6x+4 \n" ); document.write( "
Algebra.Com's Answer #146102 by RAY100(1637)\"\" \"About 
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y = x^2 +6x +4
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\n" ); document.write( "if you remember that the x vertex = -b/(2a)
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\n" ); document.write( "x= -(6)/(2 *1) = -3
\n" ); document.write( "subst into original eqn to find y
\n" ); document.write( "y = (-3)^2 +6(-3) +4
\n" ); document.write( "y= +9 -18 +4 = -5
\n" ); document.write( "therefore vertex is ( -3,-5)
\n" ); document.write( "checking, x=-2, y=4-12+4 = -4
\n" ); document.write( " x= -4, y= 16 -24 +4 = -4,,,, ok
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\n" ); document.write( "Alternate solution is to complete the square
\n" ); document.write( "y=x^2 +6x +4,,,,remember (6/2)^2 = last term
\n" ); document.write( "y-4 = ( x^2 +6x +9 ) -9
\n" ); document.write( "y-4+9 = (x+3)^2
\n" ); document.write( "(y+5) = (x+3) ^2,,,,,,,,,,form (y-k) = (x-h)^2
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\n" ); document.write( "reading directly from form, (-3,-5) \n" ); document.write( "
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