Answer:
Domain: (-infinity, +infinity) since you can pick any x values.
Range: [0, +infinity) since it does not go below the x axis.
Step-by-step explanation:
The graph is a parabola given by 
lets pick a few x values:
x = 1 gives us y = 1^2, which = 1
x = -1 gives us y = (-1)^2, which = 1
The parabola's domain is any x value as it extends to infinity.
For its range, you can see that it does not go below the x axis at x = 0. Therefore, the range of the parabola is from [0, infinity]
Answer:
so the answer is B
Step-by-step explanation:

DE. AB, is going up BC, isn't decreasing or increasing. CD, isn't decreasing or increasing. Therefore your answer is DE.
To complete the square you must split the b term in half, then square that answer.
6 is the b term, half of 6 is 3, 3 squared is 9. You will add 9 to both sides of x^2 + 6x = 15
x^2 + 6x + 9 = 24