To show the addition of the term mx to a polynomial graph, my book takes an example with y=x^3. To produce a function y=x^3 - 3x it draws the graph of y= x^3. Then the line y= - 3x is drawn in the same graph. quote" If we think of the ordinates of y=x^3 as attached to the x axis and constrained to remain vertical, the graph of y=x^3 will become the graph of y=x^3- 3x if the x axis is rotated about the origin until it coincides with the line y= -3x. Can somebody explain me in detail how rotating in such a way will produce the new graph? It mentions such transformation is shear. what is such motion? Is it applicable to all fucntions?