Respuesta :

Answer:

f(x) = (x + 1)² - 9

vertex: (-1, -9)

domain:  all real numbers

range:  y ≥ -9

Step-by-step explanation:

y = x² + 2x - 8

convert by 'completing the square' method

x² + 2x + 1 = 8 + 1

(x + 1)² = 9

f(x) = (x + 1)² - 9