Schwarz inequality proof: why is there an equals sign here?

[icystrike]

Homework Statement

This is part of the proof of Schwarz inequity.
Please help me understand the following equation , i think it should not be a equal sign instead it should be greater or equal to.

Homework Equations

The Attempt at a Solution

 

[icystrike]

will someone clear my doubt ? thanks in advance

 

[mrbohn1]

No - the equals is correct. The norm is taken by multiplying out using the dot product (so a x b = a^Tb).

 

[icystrike]

No - the equals is correct. The norm is taken by multiplying out using the dot product (so a x b = a^Tb).

Thanks mrbohn. (: