cxd-12页例三

A sequence of operations{A1,A2,...}is defined as follows A1(x)=x, A2(x)=2x^2,..An(x)=nx^n. If A2 is performed on x, and then A4 is performed on the result, what is the final result?

F(x) is performed on y, 意思是不是F(y)

谢啦