Theorem
A function
changes most rapidly in the direction of
Proof
If
and
then 
since
is a unit vector.
where
is the angle between
and
Noteis a unit vector.
Hence
is greatesat when
and
Call Us 07766496223
Theorem
A functionchanges most rapidly in the direction of
Proof
Ifand then sinceis a unit vector.
whereis the angle betweenand
Noteis a unit vector.
Henceis greatesat whenand