What is the vertex of the graph of y = x2 + 4x-1

Question

asked Jun 10, 2021 32.1k views

2 Answers

Apotek · Answer 1 · 2021-06-11T07:52:09+0000

Answer:

vertex = (- 2, - 5 )

Explanation:

Given a quadratic in standard form , y = ax² + bx + c : a ≠ 0

Then the x- coordinate of the vertex is

x_(vertex) = -
(b)/(2a)

y = x² + 4x - 1 ← is in standard form

with a = 1 and b = 4, thus

x_(vertex) = -
(4)/(2) = - 2

Substitute x = - 2 into y for corresponding value

y = (- 2)² + 4(- 2) - 1 = 4 - 8 - 1 = - 5

vertex = (- 2, - 5 )