Question

What is the vertex of `y= x^2 - 4x- 15`?

Answer 1

(2 , -19 )

Explanation:

this is a quadratic function of the form `ax^2 + bx + c`

here a = 1 and b = -4
the x-coordinate of the vertex can be found using x = - b/2a

x = -( -4/2 )= 2
and y = `2^2 - 4 xx2 - 15`
y = 4 - 8 -15
y = -19