Let f (x) = x - 3x. Round all answers to 2 decimal places. a. Find the slope of the secant line joining (3, f (3) and (9, f (9)). Slope of secant line = b. Find the slope of the secant line joining (6, f (6)) and (6+h, f (6+ h)). Slope of secant line = c. Find the slope of the tangent line at (6, (6)). Slope of the tangent line = d. Find the equation of the tangent line at (6, f (6)). y Question Help: Message instructor Post to forum