Question

Can someone pretty please help me find the domain and range of these 3 functions:

y= 1 / x-3
y= 2 * 2^x - 4
y= -√x+5 - 3

Thanks for looking!

Answer 1

y=1/x-3
to find domain of y
\[x-3 \neq 0\]
\[x \neq 3\]
so domain R-{3}

Answer 2

Wait, what? What do those symbols mean and whats "R" represent? This isn't how we learned it. o.O

Answer 3

R is the set of all real numbers

Answer 4

so would it be like: All real numbers less than three?

Answer 5

no.. all real numbers except 3

Answer 6

hmm, I'm confused. The way we learned it is you write the answer like "Domain: 3 < X "

Or something like that.. You know what I mean?

Answer 7

and to find range:
y=1/(x-3)
Domain of x is range of y

Answer 8

so by writing 3<x , we mean that x should always be greater than 3
but here it can take any value except 3 so we write this as R-{3}

Answer 9

i think you got it.
now should i move to range??

Answer 10

Ok so the answer for domain is: R-{3}? That's what I write down? If so yeah, I'll try range I guess.

Answer 11

what you are saying above can be written in your 3rd question
\[y=-\sqrt{x+5}-3\]
so here because square roots of negative number is imagingary
so x+5>0
x>-5
so it can be written here
that domainof y is x>-5

Answer 12

@neer2890, oo ok thanks! So would the range for that one be -4 < x

Answer 13

huh?

Answer 14

@neer2890 Where did you go? You were really helping! :)

Answer 15

xD