1.
The maximum and minimum values of the function f:R→Rf : \mathbb{R} \to \mathbb{R} defined by f(x)=5cos⁡x+3cos⁡(x+π3)+8f(x) = 5\cos x + 3\cos\left(x + \frac{\pi}{3}\right) + 8 for all x∈Rx \in \mathbb{R}, are respectively