I want to take the derivative of:

$\frac{d}{df}\big( \int\_{X} f^{2}(x\_{1} - x) dx - 2\int\_{X} g(x)f(x\_{1} - x)dx \big)$ 

Where $X \subset \mathbb{R}$, and $f,g: \mathbb{R} \rightarrow \mathbb{R}$. 

Can I simply write:

$2\int\_{X} f(x\_{1} - x) dx - 2\int\_{X} g(x)dx $ 

Or is this incorrect?