# Thread: Help with limits?

1. ## Help with limits?

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!

2. ## Re: Help with limits?

I think you posted the wrong image

3. ## Re: Help with limits?

Originally Posted by Shakarri
I think you posted the wrong image
Thanks! I fixed it

4. ## Re: Help with limits?

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