It is given that f(x)=x(x−b)(x+4)f(x) = x(x - b)(x + 4)f(x)=x(x−b)(x+4) where 0<b<40 < b < 40<b<4.
Sketch the curve with equation y=f(x)y = f(x)y=f(x), showing on your sketch the coordinates, in terms of b b\,b where appropriate, of the points where the curve meets the xxx-axis.
Sketch the curve with equation y=f(−3x)y = f(-3x)y=f(−3x).
State, in terms of b b\,b where appropriate, the coordinates of the points where the curve y=f(−3x)y = f(-3x)y=f(−3x) meets the xxx-axis.