Question

For real numbers \[a _{1},a _{2},...a _{n} and b _{1},b _{2},...b _{n}\] show that: \[\sum_{i-1}^{n}a _{i}b _{i}\le(\sum_{i-1}^{n}a _{i}^{2})^{1/2}(\sum_{i-1}^{n}b _{i}^{2})^{1/2}\]

Answer 1

You can use induction.

Answer 2

CS inequality.

Answer 3

http://en.wikipedia.org/wiki/Cauchy%E2%80%93Schwarz_inequality

Answer 4

Can someone please explain this problem for me please?