how to use vpasolve to solve the equation sin(x)==0 in the range of (0,5] instead of [0,5]?
조회 수: 3 (최근 30일)
이전 댓글 표시
I want to solve sin(x)=0 in the open interval of (0,5], but it seems vpasolve supports close interval only. So it is not able to give the answer I want.
Of course we can use solve and assume instead, but in my real case I have to use vpasolve because of accuracy reason.
댓글 수: 2
Dyuman Joshi
2023년 9월 23일
"Of course we can use solve and assume instead, but in my real case I have to use vpasolve because of accuracy reason."
Can you elaborate on this?
Are you saying that there accuracy issues when using symbolic variables with solve?
답변 (1개)
Walter Roberson
2023년 9월 23일
vpasolve() does not support open or semi-open intervals.
The trick is to use
syms x
sol = vpasolve(sin(x)==0, x, [1e-63 5])
I do not understand at the moment why left bounds smaller than 1e-63 appear to be treated as 0, even if you state them symbolically such as sym(10)^-80
댓글 수: 9
David Goodmanson
2023년 9월 23일
편집: David Goodmanson
2023년 9월 24일
syms x
sol = vpasolve(sin(x)/x==0, x, [0 5])
sol =
3.1415926535897932384626433832795
Ok, admittedly it's a method particular to this problem. On the other hand it doesn't hurt to keep in mind that zeros can be removable, just as poles can be removable.
Walter Roberson
2023년 9월 23일
That suggests,
syms x
sol = pi * vpasolve(sinc(x) == 0, x, [0 5/pi])
참고 항목
카테고리
Help Center 및 File Exchange에서 Calculus에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!