Find a possible formula for the quadratic function whose graph has vertex left parenthesis 8 comma 2 right parenthesis and y intercept negative 11?

Answer 1

Using the vertex (h, k) the equation of the quadratic would be:

y = a(x - h)² + k

→ y = a(x - 8)² + 2

→ y = a(x² - 16x + 64) + 2

→ y = ax² -16ax + 64a + 2

Using the y-intercept of (0, -11):

-11 = a 0² - 16a 0 + 64a + 2

→ 64a = -13

→ a = -13/64

Thus the quadratic could be:

y = (-13/64)x² - 16(-13/64)x + 64(-13/64) + 2

→ y = (-13/64)x² + (13/4)x - 11

Or, removing the fractions: 64y = -13x² + 208x - 704

Answer 2

One possible formula is 64y + 13x^2 - 208x + 704 = 0