Question

Help help xx

Answer 1

To find the rang and domain of graphs like these, you need to see the "end results". So as the value x increases, what does the graph do? Does it move up or down? This would be the domain.

Answer 2

For the range on the second graph, as the y value increases, what does the end result look like? does it go left or right?

Answer 3

it would be written somewhat like this (note this is not going to be your answer), (Infinity, infinity) (you may see the infinity sign, a side ways 8) but to translate that would look like, "as x approaches infinity, the end result is positive"

Answer 4

the graph would go on forever, but in a positive manner, XD does this help, your a little quiet.

Answer 5

No not quiet just trying to understand

Answer 6

Ok, for your specific graph, the domain (x value), as x increases, you are going to the right of the graph, as you go right, does your graph go up or down??

Answer 7

Do you have any answer choices??

Answer 8

nope

Answer 9

Ok then, as the graph moves to the right, your graph goes down towards infinity, -infinity

Answer 10

okay so that would mean what that it would be a negative and then positive?

Answer 11

the domain, as x increases, the y value decreases

Answer 12

Might be well to review the definitions of "range" and "domain" first.

"Range" refers to the SET of values that the function can take on. For example, the function y=x^2, a parabola that opens up, begins at y=0 and can have any positve y value; we write the "range" as [0, infinity).

Are you able to explain what "domain" means?

Answer 13

set of x values that rise to real y values

Answer 14

Good start. Set of values of the independent variable (x) for which the given function is defined. If, for example, you were to draw a vertical line through x=2 on the graph of y=x^2, you'd get y = 4 = 2^2. Y is defined for x=2, so x=2 is part of the domain of that function.

Answer 15

Okay

Answer 16

If, on the other hand, you had a function such as y=3 / (x+2), x=-2 would NOT be in the domain of that function. Can you explain why? Review the definition of "domain," above.

Answer 17

\[y=\frac{ 3 }{ x+2 }\]

Answer 18

Because of the negative numbers

Answer 19

Hint: Substitute -2 for x in the denominator of the above function.

Answer 20

Well -2+2 is 0

Answer 21

True. How would you respond (react) to 3/0?

Answer 22

well no answer

Answer 23

@mathmale

Answer 24

For Q3, the range are all the y-values of the curve.
as you can see, the curve goes "down" forever
y goes from -infinity up to a max y value (which you can read off the graph)

can you figure out the range for Q13 ?

Answer 25

y vallues??

Answer 26

Because the curve does go down

Answer 27

@phi

Answer 28

y values because the question asks about the RANGE
in other words, range is all the y-values that the curve "uses"

Answer 29

well for y doesn't it use 1,2,3

Answer 30

for Q13, the curve uses all y values 3 and smaller

Answer 31

So 3 and less than?

Answer 32

we would write that as
\[ ( -\infty, 3]\]
the ( means infinity is never "reached"
the ] means we do reach 3 (but don't go bigger than 3)

Answer 33

oh so the answer for Q13 would be negative infinity,3?

Answer 34

yes, but with ( and ]

Answer 35

Oh okay, and then what about Q14

Answer 36

for Q14, they ask about the domain
that is all the x-values used.
can you figure out what x-values are used ?

Answer 37

yes, but with ( and ]

Answer 38

we would write that as
\[ ( -\infty, 3]\]
the ( means infinity is never "reached"
the ] means we do reach 3 (but don't go bigger than 3)

Answer 39

for Q13, the curve uses all y values 3 and smaller

Answer 40

4 and all numbers smaller

Answer 41

yes, and how do you write that ?
-infinity to 4
or
\[ (-\infty, 4]\]

Answer 42

the second one

Answer 43

yes, I was just writing it in "English" when I wrote -infinity to 4
and then using "math"

Answer 44

so that would be the domain of the relation graphed right?

Answer 45

yes.