11. For the function $f(x)$, for any $x_{1}, x_{2}\left(x_{1} \neq x_{2}\right)$ in its domain, the following conclusions are drawn:
(1) $f\left(x_{1}+x_{2}\right)=f\left(x_{1}\right) \cdot f\left(x_{2}\right)$
(2) $f\left(x_{1} \cdot x_{2}\right)=f\left(x_{1}\right)+f\left(x_{2}\right)$
(3) $\frac{f\left(x_{1}\right)-f\left(x_{2}\right)}{x_{1}-x_{2}}>0$
(4) $f\left(\frac{x_{1}+x_{2}}{2}\right)>\frac{f\left(x_{1}\right)+f\left(x_{2}\right)}{2}$

When $f(x)=10^{x}$, the correct conclusions among the above are $\qquad$
11. (1),(3)