Answer
-5.26
Work Step by Step
The minimum or maximum value of a function is the y-value of the vertex. The x-value of the vertex is $-b/2a$.
$f(x)=7.6x^2+9.8x-2.1$
$a=7.6$, $b=9.8$, $c=-2.1$
$x=-b/2a$
$x=-9.8/2*7.6$
$x=-9.8/15.2$
$x=.645$
$f(x)=7.6x^2+9.8x-2.1$
$f(-.645)=7.6*(-.645)^2+9.8*-.645-2.1$
$f(-.645)=7.6*.416025-6.32-2.1$
$f(-.645)=3.162-8.42$
$f(-.645)=-5.258 $
$f(-.645)=-5.26$
