Intertwined Integrals

Calculus Level 1

If an antiderivative of $$f\left( x \right)$$ is $${ e }^{ x }$$ and that of $$g\left( x \right)$$ is $$\cos { x }$$, then $$\displaystyle \int { f\left( x \right) \cos { x } \ dx } +\int { g\left( x \right) { e }^{ x } \ dx }$$ is equal to

×