Question

Pls help me on this i don't know what to do ​

Answer 1

Answer:

D.

Step-by-step explanation:

Standard Form (Quadratic): $y=ax^2+bx+c$

Vertex Form (Quadratic): $y=a(x-h)^2+k$

Intercept Form (Quadratic): $y=a(x-p)(x-q)$

      p,q are x-intercepts

x-intercepts given in graph: -2,4

$y=a[x-(-2)](x-4)$

eqn 1: $y=a(x+2)(x-4)$

Plug in the given point to find 'a' : (3,-5)

$-5=a(3+2)(3-4)$

$-5=a(5)(-1)$

$1=a$

Substitute 'a' in to eqn 1.

$y=1(x+2)(x-4)$

eqn 2: $y=(x+2)(x-4)$

Expand eqn 2. (can use FOIL)

$y=x^2-2x-8$