Answer: y = one sixteenth(x − 4)^2 + 2
Step-by-step explanation:
If the parabola is written as:
y = a*x^2 + b*x + c
then if the graph opens up, then a must be positive, so we can discard the third and fourth options, we remain with:
y = 1/6*(x - 4)^2 + 2 = 1/6x^2 - (8/6)*x + (16/6 + 2)
y = 1/6*(x + 4)^2 - 2 = 1/6x^2 + (8/6)*x + (16/6 - 2)
the vertex (4, 2)
then
x = -b/2a = 4.
this means that a and b must be of different sign, then the only correct option can be:
y = 1/6*(x - 4)^2 + 2 = 1/6x^2 - (8/6)*x + (16/6 + 2)
where:
x-vertex = (8/6)/(2/6) = 4 as we wanted.
when we evaluate this function in x = 4 we get
y = 1/6*( 4 - 4)^2 + 2 = 2.
So the correct option must be: y = one sixteenth(x − 4)2 + 2
