Find f'(x) and find the equation of the line tangent to the graph of f at the indicated value of x. Find the value(s) of x where the tangent line is horizontal. f(x) = In (12-9x2 + 2x4) ; x= 1 f' ( x ) = The equation of the line tangent to the graph of fat x = 1 is y = Select the correct choice below and fill in any answer boxes in your choice. O A. The value(s) of x where the tangent line is horizontal is/are (Simplify your answer. Use a comma to separate answers as needed.) O B. The tangent line is never horizontal