Question 403910
The x-coordinate of the vertex of an equation with the form
{{{y = ax^2 + b*x + c}}}
Is {{{x = -b/(2a)}}}
(a)
{{{y =  x^2 - 14x - 95}}}
{{{a =  1}}}
{{{b = -14}}} 
{{{-b/(2a) = -(-14)/(2*1)}}}
{{{-b/(2a) = 7}}}
So far I have (7,y)
To find {{{y}}}:
{{{y = 7^2 - 14*7 - 95}}}
{{{y = 49 - 98 - 95}}}
{{{y = -144}}}
The vertex is at (7,-144)
The plot is:
{{{ graph( 400, 400, -8, 20, -150, 10, x^2 - 14x - 95) }}}
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(b)
{{{y = 2x^2 + 16x + 21}}}
{{{-b/(2a) = -16/4}}}
{{{-b/(2a) = -4}}}
So far I have (-4,y)
To find {{{y}}},
{{{y = 2*(-4)^2 + 16*(-4) + 21}}}
{{{y = 32 - 64 + 21}}}
{{{y = -11}}}
The vertex is at (-4,-11)
The plot is:
{{{ graph( 400, 400, -10, 2, -12, 5, 2x^2 + 16x + 21) }}}