清空筛选条件
清空筛选条件

Inconsistent results from "int" function

1 次查看（过去 30 天）
YoungJoo Lee
YoungJoo Lee 2022-11-27
评论： YoungJoo Lee 2022-11-27
Hi, everyone. For the same question, the "int" function provided me with different results.
syms x y
int(x*y/24+y^2/48,x)
int((y*(2*x + y))/48,x)
The second line gave me "(x*y*(x + y))/48" which was what I originally wanted,
but the third line gave me "'(y*(2*x + y)^2)/192" which is wrong.
Can anyone explain the reason?
Thanks for your time and help in advance!

请先登录，再回答此问题。

采纳的回答

Alan Stevens
Alan Stevens 2022-11-27
You can express '(y*(2*x + y)^2)/192 as (x*y*(x + y))/48+y^3/198
As far as the integral is concerned y is a constant, so the two results are the same to within a constant, which is all you can guarantee from an integral with no specific limits.
  5 个评论
显示 3更早的评论
Torsten
Torsten 2022-11-27
I believe, for my problem, providing something like "(x*y*(x + y))/48+C (where C is a constant)" as output would be more appropriate.
"(x*y*(x + y))/48+C(y) (where C is a function solely depending on y)"

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by