Question

What is the vertex of y= -x^2 - 4x - 1?

Answer 1

This requires completing the square.

y = -(x^2 + 4x + ______) - 1 + ________

Answer 2

My teacher had explained that the vertex could be calculated by doing this equation: -b/2a

Answer 3

Well, then why didn't you do that? Completing the square will prove where that came from. If you already believe, then let's see it.

Answer 4

btw "-b/2a" is not an equation. It is an expression.

The x-coordinate of vertex can be found by evaluating x = -b/2a