Domain and range word problems

Question

the value v (in dollars) of a washer/dryer set decreases as a function of t in years). the function v(t)=-100t+1200 models this situation. you own the washer/dryer set for 12 years. what is a reasonable domain for the problems situation. write the answer in words.

Answer 1

Ok, so to find a reasonable domain, I would look at both the v and t intercepts. I'll explain here:

So we know that the value of a dryer starts off at $1200 at time 0, so 0 would be a part of the domain. We got that by simply plugging 0, therefore getting us our v intercept, which was 1200. Then we find our t intercept, which we get by setting v(t)=0. So now we are left with 0=-100t + 1200, and we know when we solve the problem, we get t=12. So our domain would be from 0 to 12. I hope that helped you!