Question 194728: How do you find the vertex of y=x^2+6x+4
Answer by RAY100(1637)   (Show Source):
You can put this solution on YOUR website! y = x^2 +6x +4
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if you remember that the x vertex = -b/(2a)
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x= -(6)/(2 *1) = -3
subst into original eqn to find y
y = (-3)^2 +6(-3) +4
y= +9 -18 +4 = -5
therefore vertex is ( -3,-5)
checking, x=-2, y=4-12+4 = -4
x= -4, y= 16 -24 +4 = -4,,,, ok
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Alternate solution is to complete the square
y=x^2 +6x +4,,,,remember (6/2)^2 = last term
y-4 = ( x^2 +6x +9 ) -9
y-4+9 = (x+3)^2
(y+5) = (x+3) ^2,,,,,,,,,,form (y-k) = (x-h)^2
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reading directly from form, (-3,-5)
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