According to the "power rule" of inegral calculus: to integrate a term with respect to "x" you must take the existing power of the "x" portion of the term, and raise it by one. You must then divide the whole term by its new power or multiply the whole term by 1 divided by the new power:
If the term is 2x, the x portion of the term has a power of 1, so we raise that power to 2 and multiply the whole term by 1/2. which gives us:
Thus in our equation: R2X0 will become 1/1R2X1 or merely R2X which is the correct integral for the first term, while X2 will become 1/3X3 ,the correct integral for the second term.