Let $f,g : [0,1] \to $ R be continuous functions.
show that $||fg|| \le ||f||||g||$.
So what I know and found out :
The absolute value is a particular instance of the norm. So, $||x||= |x|$
Suppose I take -
$f(x)=5$ and $g(x)=2$ be continuous for all x $\in[0,1]$
Then
$|f(x)|=|5| $ and $|g(x)|=|2|$
$|fg|=|5\times2|=|10|=10$
$|f||g|=|5||2|=5\times2=10$
hence, $|fg|=|f||g|$, and from $||x||= |x|$,
we get : $||fg||=||f||||g||$
but how do I proof ? $||fg||<||f||||g||$. Am I to use triangle inequality ?