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Question 1105216: Could you please help with this math problem. I have to state the domain and range, the y-intercept, and say whether or not it's a function:
Jordon weighs 160 lbs. By lifting weights each month for a year, he continually gains weight until he is 200 lbs.
{x|
{y|
y-int:
Function - yes or no
I think that the y-intercept is (0, 160) and I think that it is a function because it is a linear equation because he is continually gaining weight each month. I am not sure what the domain and range would be nor am I clear on what the equation would look like. I think the range would be {y| 160 ≥ x ≤ 200}. Would the domain be {x| x >0} ?
Could you please help.
Thank you!
Found 2 solutions by Boreal, greenestamps:
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! So long as in a given month he does not have two different weights, it is a function.
The y-intercept is as you wrote, (0, 160)
The domain is [0, 12]. If he keeps track of his weight after that, the domain is appropriately larger.
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
Could you please help with this math problem. I have to state the domain and range, the y-intercept, and say whether or not it's a function:
Jordon weighs 160 lbs. By lifting weights each month for a year, he continually gains weight until he is 200 lbs.
The thing being watched is Jordon's weight as time goes by for a year. We don't know whether his weight gain is linear; we only know it is 160 at the beginning of the year and 200 at the end. So...
domain: His weight is being monitored over the course of a year; however, it is not clear what the domain should be, because we don't know how often his weight if begin measured. But the problem says he is "lifting weights each month for a year", which IMPLIES that "months" should be the unit in the x direction on the graph. Since he is monitoring his weight for 1 year (12 months), the domain is [0,12]. Of course the domain will be different if he continues to monitor his weight after the one year.
range: From his beginning weight to his ending weight -- [160,200]. Since the problem doesn't say he gains weight at a constant rate, we can't be sure that is the right answer. At the beginning of the year, he might have dipped below 160 for some reason initially; and/or at the end of the year he might have gone a bit over 200. So we can't be sure [160,200] is the actual range -- but it's the only answer we can give with the given information.
y-intercept: His weight at the beginning, 160.
function?: Yes; at any time during the year he only had one weight.
You say you don't know what the equation would be; and in fact we don't know what it would be, because we don't know that his weight gain was at a constant rate (and in reality it is very unlikely that it was).
Finally a note about how you show one of your answers.... The statement  does not say what you want it to. You want it to say that x is greater than or equal to 160 and less than or equal to 200; but the way you write it says it is less than 160 and less than 200 -- which not only doesn't make sense, it is also wrong. The correct way of writing that answer is  .
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