10 The table below is for y=x^2-4x-1 . (a) Complete the table. (b) Using a scale of 2 cm to 1 unit, draw a horizontal x-axis for -2 =<x =< 6. Using a scale of 2 cm to 5 units, draw a vertical y-axis for -10=< y =< 15. Plot the points from the table and join them with a smooth curve. (c) By drawing a tangent, estimate the gradient of the curve at x = 3. (d) (i) Find the least value of y. (ii) y =<4 for a =< x =< b. Find the least possible value of a and the greatest possible value of b. (e) Use your graph to solve the equation x^2-4x+2=0. Show your working to explain how you used your graph.