y=13x46x2 + 1; (-1, 8) (a) Find an equation of the tangent line to the graph of the function at the given point. y = (b) Use a graphing utility to graph the function and its tangent line at the point. Use the tangent feature of a graphing utility to confirm your results. O-2.0 -1.5 -1.0 -0.5 Χ y 30年 20 25 20 -1.4 -1.2 -1.0 -0.8 0.6 -0.4 -0.2 -20 15 -40 10 5 -60 -80 x -100 y y x -1.4 1.2 -1.0 -0.8 0.6 0.4 -0.2 30 -20 25 20 -40 15 -60 10 5 -80 -2.0 -1.5 -1.0 -100 -0.5 ×