Question

Evelyn walks on a treadmill for at least 1 hour but not more than 2 hours. She walks at an average rate of 3.5 miles per hour. The distance Evelyn walks in t hours is represented by a function.



r(t)=3.5t



What is the practical domain of the function?

All real numbers.

All real numbers from 1 to 2, inclusive.

All integers from 1 to 2, inclusive.

All multiples of 3.5 between 3.5 and 7, inclusive.

Answer 1

think about it, I have shown a few of these

Answer 2

integers are whole numbers, so deffinetly use those in domains

Answer 3

at least 1, at most 2... hhmmm?

Answer 4

sorry my wifi is messing up

Answer 5

i think it is B

Answer 6

no, remember, integers

Answer 7

You need to know two main things for this problem:

1) The time needs to be \(\text{1 hour} \le x \text { } \le \text{2 hours}\) because she can be on the treadmill for at least 1 hour but not more than 2 hours (which means she must stop at 2 hours).

2) Ask yourself: Can time be represented as a decimal or can it only be represented as integers?

Answer 8

oooooooohhh... but it says practical, earlier I was with @newmar and it said just "domain"

Answer 9

oo ok C all integers

Answer 10

I gtg, good luck!

Answer 11

ok thx

Answer 12

Nope it is not C

Answer 13

so not integers

Answer 14

I can say time to be as 1 hour or 1.5 hours if I'd like.

Answer 15

talk to @calculusxy , he knows

Answer 16

@TGstudios It's a "she"

Answer 17

Since time can also be represented as decimals, we know that it cannot only be limited to integers. Therefore, since real numbers also include decimals it must be that it's all real numbers between 1 and 2, inclusive.

Answer 18

wait it is B i said that in the beginning

Answer 19

thank you