MATLAB int function problem while evaluating a symbolic definite integral

조회 수: 16 (최근 30일)
this is my code
syms x y z b
assume(b, 'positive')
h(x,y,z) = z /(x^2 + y^2 + z^2)^(3/2) ;
int(h, x , [0 b])
i want to get the result of this integral wich is:
(2 b z)/((y^2 + z^2) Sqrt[b^2 + y^2 + z^2])
but instead i get :
ans(y, z) =
piecewise(y^2 + z^2 == 1 & ((z^2)^(1/2) == z | z + (z^2)^(1/2) == 0), (b*z)/(b^2 + 1)^(1/2), y^2 + z^2 ~= 1 | (z^2)^(1/2) ~= z & z + (z^2)^(1/2) ~= 0, int(z/(x^2 + y^2 + z^2)^(3/2), x, 0, b))
what can i do to get the first answer ? is there something wrong in my code ?
  댓글 수: 1
Walter Roberson
Walter Roberson 2020년 9월 10일
Your proposed answer is not correct when there are certain relationships between the complex values x, y, z .
You have the assumption that b > 0, which implies that b is real, but the calculation needs to take into account that x, y, z are complex.

댓글을 달려면 로그인하십시오.

채택된 답변

Walter Roberson
Walter Roberson 2020년 9월 10일
simplify(ans, 'steps', 100)

추가 답변 (0개)

카테고리

Help CenterFile Exchange에서 Numerical Integration and Differentiation에 대해 자세히 알아보기

제품


릴리스

R2020a

Community Treasure Hunt

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

Start Hunting!

Translated by