Answer
$(-.65, -5.26)$
Work Step by Step
$f(x)=7.6x^2+9.8x-2.1$
The highest (or lowest) point on a graph is found using the vertex of a graph. The vertex of the graph has the equation $x=-b/2a$.
$a=7.6$, $b=9.8$, $c=-2.1$
$x=-b/2a$
$x=-9.8/2*7.6$
$x=-9.8/15.2$
$x=-.6447$
$f(x)=7.6x^2+9.8x-2.1$
$f(-.6447)=7.6(-.6447)^2+9.8(-.6447)-2.1$
$f(-.6447)=7.6*.4156-6.318-2.1$
$f(-.6447)=3.15856-8.418$
$f(-.6447)=-5.259$