Question 934253
{{{ f(x) = x^2 - 10x + 16 }}}
When form is:
{{{ f(x) = a*x^2 + b*x + c }}}, then 
then {{{ x[ vertex] = -b / (2a) }}}
{{{ a = 1 }}}
{{{ b = -10 }}}
{{{ c = 16 }}}
{{{ -b/(2a) = -(-10) / ( 2*1 ) }}}
{{{ -b / (2a) = 10 / 2 }}}
{{{ -b / (2a) = 5 }}}
Now find {{{ y[vertex] }}}
{{{ y[vertex] = 1*5^2 - 10*5 + 16 }}}
{{{ y[vertex] = 25 - 50 + 16 }}}
{{{ y[vertex] = -9 }}}
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The vertex is at ( 5, -9 )
Here's the plot:
{{{ graph( 400, 400, -10, 10, -10, 10, x^2 - 10x + 16 ) }}}