高数问题(x^2+1/2x^4+o(x^4))*(x-1/6x^3+o(x^3))=x^3+1/3x^5+o(x^5)请问这是怎样计算的?

Question

高数问题
(x^2+1/2x^4+o(x^4))*(x-1/6x^3+o(x^3))
=x^3+1/3x^5+o(x^5)
请问这是怎样计算的?

Answer 1

乘出来,高于5次的舍去
=x^3-1/6x^5+1/2x^5+o(x^5)
=x^3+1/3x^5+o(x^5)