Question

Algebraically find the vertex of y= -2x^2 + 4x + 1? pls show work

Answer 1

The vertex we want must be in the form of the point (-b/2a, y).

1. Find x.

x = -b/2a

x = -4/2(-2)

x = -4/(-4)

x = 1

2. Replace every x in the given function with 1 to find y.

y = -2(1)^2 + 4(1) + 1

y = -2 + 4 + 1

y = -2 + 5

y = 3

Our vertex is the point (1, 3).

Understand?