x-intercepts of f(x) are

As points they are (-2,0) and (-4,0)
y-intercept of f(x) is

As a point it is (0,8)
x-intercepts of g(x) are:

y-intercept of g(x) is:

As a point it is (0,3)
f(x) has a minima, the function is cap-sized. Since we have a simple case of quadratic function, there is no need to check the second order derivative. Indeed, I will attach both graphs for f(x) and g(x). The minima of f(x) is (-3,-1). And g(x) has a maxima. This maxima is the point (2,11)