Find the domain and range?

Question

find the domain and range of this line

it shows a graph but ill just describe it to you.

its a ray..

its endpoint is at (-6, -2)

it runs through (8, 2)

but its a ray so it has an arrow.

looks kind like this *---------> its increasing

tell me if you need more info to figure this out.

Answer 1

The ray actually starts at its "endpoint," (-6 , -2) and goes onto infinity.

The domain is x>-6, or [-6,infinity)

The range is x>-2, or [-2, infinity)

Answer 2

It starts at (-6,-2), and then x and y will both increase forever. Assuming the point is closed, the domain is [-6,infinity) and the range is [-2,infinity). If the point is open, then it's (-6, infinity) and (-2,infinity). Hope this helps!

Answer 3

Well, the "domain" is the input x, where the "range" is the output y.

Given that you know its endpoint and a point that it runs through, you can set up an equation for it.

For a line, this is y = mx + b

Where m is the slope, x is the input (domain), b is the y-intercept, and y is the output (range).

For slope, we just use the standard rise/run deal, since it is a line. The rise is 2 - (-2) = 4

The run is 8 - (-6) = 14

This the slope is 2/7.

So y = (2/7)x + b

Now at x = 8, we have y = 2. Thus,

2 = 16/7 + b -> 14/7 - 16/7 = b, -2/7 = b.

so y = (2/7)x - 2/7

You can verify this by plugging in -6 for x, and observe that the output is -2.

Now we have an equation, so what is the domain? Well, we have an endpoint at (-6, -2) so obviously the x cannot go lower than -6.

But x can be anything above -6. Thus, the domain is

[-6, infinity)

The range is [-2, infinity)

I guess there was no reason to do all that other stuff,but whatever.

Domain: x >= -6

Range: y >= -2

There is your answer.

Answer 4

It's a ray with a positive slope, so

x >= -6 ==> domain = [-6 , inf) , or x >= -6

y >= -2 ==> range = [-2,inf), or y >= -2