Curves: gradient: the quadratic curve y = x²+ax+b Move the sliders to move the red line or change the curve. Use the display to estimate to the nearest whole number the gradient of the following curves at the given points: y = x²+2x+1 at x=2 gradient = y = x²+3x+2 at x=-2 gradient = y = x²-3x+1 at x=3 gradient = controls