I think the answer is 75.6 because i divided 36 cards by 5 folders and i got 1.2. And then i divided 372 extra cards by 5 folders am got 74.4. I add the two total and have 75.6
5/36 = 1.2 5/372 = 74.4
1.2+74.4= 75.6 srry if I'm wrong
First of all, we can just ignore A, it has no effect but to vertically stretch our cosine.
If it was only , the function would be invertible as long as it's confined between and . Now, the argument of our cosine is not but . It means that it won't stop at , but at .
Another way to think about it, "what should i replace x with so I get inside the cosine?"