Table of Contents. So I’m assuming it’s a 4 and that’s the reason why when I’m on a 4.0 Wi-Fi it will be slow but when I’m on a 3.0 Wi-Fi it will be fast. Does that sound right? A: The really apparent explanation is that the code is written with a lot of assumptions about what version of the API you’re using. The first lines of the code are: #if VERSION_MIN == VERSION_NEXT and #if VERSION_CURRENT VERSION_CURRENT and #if VERSION_MIN == VERSION_NEXT So, if you’re running version 4.0 you’ll be one of the users that is just getting the code. If you’re running any version less than 4.0, you won’t be one of those users. Q: Prove this inequality by induction. If $a_1, a_2, a_3, \cdots, a_n$ are positive numbers such that $$a_1+a_2+a_3+\cdots+a_n=1$$ and $$a_1a_2a_3\cdots a_n=1$$ Prove that $$1+a_1+a_1a_2+a_1a_2a_3+\cdots+a_1a_2a_3\cdots a_n\ge2$$ I think that it’s an easy induction argument using that $a_1, a_2, a_3, \cdots, a_n$ are positive numbers. But I have no idea how to start proving it. Any help will be appreciated. A: Hint: Hint: $$\sum_{i=1}^{k}a_{i}^{2} =\left( a_{1}+a_{2}+\cdots +a_{k}\right)^{2} -2\left( \sum_{i=1}^{k}a_{i}\right) ^{2}$$ A: We want \$f(k)=1+a_1+a_1a