Question

PLEASE HELP!

Which of the following functions have a domain of (-∞,∞) and a range of (5,∞)?

Check all that apply.

a. f(x)=3^x+5
b. f(x)=3^x-5
c. f(x)=0.25^x+5
d. f(x)=0.25^x-5

Answer 1

all of them has the same domain (-∞,∞), but the in first one, if you replace x by positive infinity you will get positive infinity, and replacing by negative intinity you wil get 1/(3^∞) + 5, wich is something really really small plus 5, this is the range (5,∞)

Answer 2

so the answers are b,c,and d?

Answer 3

it's A, did you understand what I said before?

Answer 4

yeah it was just confusing which one you were talking about

Answer 5

right.. it's the first one

Answer 6

are you sure the others don't work because I can have multiple answers

Answer 7

let's see if they work, the 2nd option 3^x-5
3^∞-5 = ∞
3^-∞ -5 = 1/(3^∞) -5 something really smal, almost zero, minus five, this is almost equal to negative five -5, the range would be (-5,∞)

Answer 8

so no

Answer 9

the other two options are kind of the inverse

Answer 10

0.25 is the same as 1/4 right?

Answer 11

yes

Answer 12

(1/4)^∞ = 1/(4^∞) = almost zero

(1/4)^-∞ = 4^∞/1 = infinity

Answer 13

the correct options are A and C

Answer 14

thank you

Answer 15

you're welcome