Cauchy schwarz math help

[hadi amiri 4]

Homework Statement

what is the relation between cauchy_schwarz inequality and this ;
Sin(a+b)=Sin(a)Cos(b)+Cos(a)Sin(b)

Homework Equations

The Attempt at a Solution

 

[foxjwill]

Think of it as the dot product of two vectors. From that you can show that, although already obvious, $$\sin{(a+b)}\leq 1$$.