find the minimum or maximum value of the function f(x)=4x^2+x-5

Answer 1

Find the y coordinate of the vertex

a = 4

b = 1

c= -5

The vertex has coordinates ( -b/2a, f(-b/2a))

So the max/min value is f (-b/2a)

As a>0 the parabola faces upwards, so it will be a minimum