Question

For the function f(x) = –2(x + 3)2 − 1, identify the vertex, domain, and range.

The vertex is (3, –1), the domain is all real numbers, and the range is y ≥ –1.
The vertex is (3, –1), the domain is all real numbers, and the range is y ≤ –1.
The vertex is (–3, –1), the domain is all real numbers, and the range is y ≤ –1.
The vertex is (–3, –1), the domain is all real numbers, and the range is y ≥ –1.

Answer 1

the vertex form is
a(x - b) + c
where the vertes is at (b , c)

Answer 2

so the vertex is 3,-1

Answer 3

also the function in the question is a parabola opening downwards because of the negative term -2

Answer 4

so would it be A?

Answer 5

not quite the y coordinate is correct
but if we compare (x - b) to (x + 3) we see that b = -3

Answer 6

so then is has to be B

Answer 7

so the vertex is (-3,-1)
The range is the possible values of y ( f(x)) - note what I said about the shape of the parabola - it opens downwards

Answer 8

how can it be be if vertex is at (-3,-1)?

Answer 9

* how can it be B?

Answer 10

as i explained the vertex is at (-3,-1) not (3,-1)

Answer 11

oh okay i see now i thought the 3 was postive