Question

PLEASE ANSWER!!

A quadratic function is shown on the graph.

A. Write an equation to represent the function in vertex form.

B. Write an equation to represent the function in standard form.

Answer 1

see explanation

Explanation:

A

the equation of a quadratic in vertex form is

y = a(x - h)² + k

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

here (h, k ) = (1, - 4 ) , then

y = a(x - 1)² - 4

to find a substitute the coordinates of any other point on the graph into the equation.

using (0, - 3 )

- 3 = a(0 - 1)² - 4 ( add 4 to both sides )

1 = a(- 1)² = a ⇒ a = 1

y = (x - 1)² - 4 ← in vertex form

B

the equation of a quadratic in standard form is

y = ax² + bx + c ( a ≠ 0 )

using the result from A

y = (x - 1)² - 4 ← expand the factor using FOIL

= x² - 2x + 1 - 4

y = x² - 2x - 3 ← in standard form