Hi, I'm stuck in the following problem: I have considered, for h>0:
I have considered, for h>0:
$\frac{\varphi(f(x)+t g(x))-\varphi f(x)}{t} $
While on the other way: $\frac{\varphi(f(x)+t g(x))-\varphi f(x)}{t}\ge$ But now? These inequalities don't give me information... $\frac{\varphi(f(x)+t g(x))-\varphi f(x)}{t} \le $ . Where $f$ and $g \in C^0 ([a,b],\mathbb{R})$.
I have considered, for h>0:
$\frac{\varphi(f(x)+t g(x))-\varphi f(x)}{t} $
While on the other way: $\frac{\varphi(f(x)+t g(x))-\varphi f(x)}{t}\ge$ But now? These inequalities don't give me information...

