For this question: I'm having a lot of trouble because I got that x's limit to infinity and -infinity was 100. Making III and IV right, but that isn't an option. What am I doing wrong? Thanks!
Last edited by canyouhelp; Mar 16th 2014 at 05:37 PM.
Let's think about this, as x approaches infinity what happens to the term 3000(a)^x?
Spoiler:
It gets very close to zero since a is 0< a <1 and this is a decreasing exponential function. So, 3000 x a very small number = very very small it is negligible. So just solve f(x) = 100 - (12000/400) = 70