12. Determine the rule of the quadratic functionſ given the following information:
• When f(x) = ax^2+ bx+c, b2 = 4ac
• f(x) bigger than or equal to 0 for XER
• f(x) has an axis of symmetry of x = -5
• f(-1)=4

f(x) = ¼ x² + ⁵/₂ x + ²⁵/₄

Step-by-step explanation:

b² = 4ac, so the discriminant is 0.  That means the quadratic has a repeated root, which is the vertex.

f(x) has an axis of symmetry of x = -5.  That means the x-coordinate of the vertex is -5.

So f(x) = a (x + 5)².

f(-1) = 4, so the value of a is:

4 = a (-1 + 5)²

4 = 16a

a = ¼

The function is  f(x) = ¼ (x + 5)².  Converting to standard form:

f(x) = ¼ (x² + 10x + 25)

f(x) = ¼ x² + ⁵/₂ x + ²⁵/₄

fourth month

step-by-step explanation:

it is the one with the most keychains.

answer: f true

step-by-step explanation: