solve by substitution method

6 次查看（过去 30 天）
angie
angie 2011-3-16
编辑： Walter Roberson 2018-9-16
4x+5y=-15
x=3-8y

请先登录，再回答此问题。

回答（3 个）

Matt Fig
Matt Fig 2011-3-16
Do you have a question? One related to MATLAB?
  2 个评论
Matt Tearle
Matt Tearle 2011-3-16
attack of the Matt Police!
Matt Fig
Matt Fig 2011-3-16
HaHa, I didn't even see your first comment till now!

请先登录，再进行评论。

Walter Roberson
Walter Roberson 2011-3-17
syms x y
yexpr = solve(4*x+5*y+15*x,y);
xval = solve(subs(3-8*y+15*x,yexpr),x);
yval = solve(subs(4*x + 5*y + 15*x, x, xval),y);
(There is at least one shorter method.)
omer ozdemir
omer ozdemir 2018-9-15
编辑：Walter Roberson 2018-9-15
how can be solved this problem?
suppose that a polynominal can be expressed by
f(x)= x^5+3*x^4+4*x^3+2*x^2+3*x+6
If one wants to substitute x by s-1/s+1, the function f(x) can be changed into a function of s.
thanks.
  2 个评论
Walter Roberson
Walter Roberson 2018-9-15
You can use subs() and simplify() from the Symbolic toolbox.
Note that f(s) will not be a polynomial.

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Calculus 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