Q4) Let f(x) = In(x2 - 16) for x > 4. [5 marks] The graph below shows the graph of f(x) which crosses the x-axis at point A with coordinates (a, 0). The line L is a tangent line that intersects the graph at point B. a) Find the coordinates of A. [2] B A(a, 0) b) Given that L has a slope of =, find the x-coordinate of B. [3]