Q4: You need to review the geometrical applications of differentiation topic.
f(2) = 8 implies that at x = 2, the function value f(x) is 8, i.e. (2,8)
f'(2) = 6 > 0 implies the function is increasing at x = 2, i.e. sloping upwards
f''(2) = 2 > 0 implies the function is concave up at x = 2, i.e...