Consider the quadratic function:

f(x) = x2 – 8x – 9

Vertex: (StartFraction negative b Over 2 a EndFraction, f (StartFraction negative b Over 2 a))

What is the vertex of the function?

THE ANSWER IS ( ⇒ 4, ⇒ -25) ON EDGE

vertex = (4, - 16 )

Step-by-step explanation:

Given a quadratic in standard form, f(x) = ax² + bx + c : a ≠ 0

Then the x- coordinate of the vertex is

= -

f(x) = x² - 8x - 9 ← is in standard form

with a = 1, b = - 8, thus

= - = 4

Substitute x = 4 into f(x) for corresponding y- coordinate

f(4) = 4² - 8(4) - 9 = 16 - 32 - 9 = - 16

vertex = (4, - 16 )

b) 36

step-by-step explanation:

18 times 2 is 36

439400

step-by-step explanation:

130^2 = 16900

16900*26 = 439400