Complete the square in vertex form y=x^2+18x-2

y = (x + 9)² - 83

Step-by-step explanation:

The equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

Given

y = x² + 18x - 2

Obtain vertex form by using the method of completing the square

add/subtract (half the coefficient of the x- term )²

y = x² + 2(9)x + 81 - 81 - 2

  = (x + 9)² - 83