Hey guys, I have a word problem I'm confused/ stuck on.

A video game company is selling a new console, the sales of the the system will follow the quadratic function y = -1/50x^2+7x-200.

1. After how many days is the company going to make a profit?

2. After how many days do they reach their peak sales?

3. How many days can they expect to be making a profit on this product?

4. What is a reasonable domain and range for this?

So I started out with -b/2a. I got 175 and plugged it into the equation and ended up with 412.5.

I'm confused because I don't know if I found the answer to # 1 or # 2. I'm guessing I got the maximum for # 2, but what would I find for number 1?

And the rest I have no clue on what to do.

Sorry if this sounds confusing.