The Square Norm of the Function $f ( x ) = 1 - x$

Multiple Choice

The square norm of the function $f ( x ) = 1 - x$ on the interval $[ 0,2 ]$ is

A) 2/3
B) $\sqrt { 2 / 3 }$
C) 1/3
D) $\sqrt { 1 / 3 }$
E) 0