Answer:
y = (x - 3)² + 6
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
Using the method of completing the square
y = x² - 6x + 15
add/subtract ( half the coefficient of the x- term )² to x² - 6x
y = x² + 2(- 3)x + 9 - 9 + 15
y = (x - 3)² - 9 + 15
y = (x - 3)² + 6 ← in vertex form
