英语翻译FINVERSE Functional inverse.g = FINVERSE(f) returns the functional inverse of f.f is a scalar sym representing a function of exactly one symbolic variable,say 'x'.Then g is a scalar symthat satisfies g(f(x)) = x.g = FINVERSE(f,v) uses the

英语翻译FINVERSE Functional inverse.g = FINVERSE(f) returns the functional inverse of f.f is a scalar sym representing a function of exactly one symbolic variable,say 'x'.Then g is a scalar symthat satisfies g(f(x)) = x.g = FINVERSE(f,v) uses the
英语翻译
FINVERSE Functional inverse.
g = FINVERSE(f) returns the functional inverse of f.
f is a scalar sym representing a function of exactly
one symbolic variable,say 'x'.Then g is a scalar sym
that satisfies g(f(x)) = x.
g = FINVERSE(f,v) uses the symbolic variable v,where v is
a sym,as the independent variable.Then g is a scalar
sym that satisfies g(f(v)) = v.Use this form when f contains
more than one symbolic variable.
If no inverse can be found g is either the empty sym object
or,if f is a polynomial,a RootOf expression.
Examples:
finverse(1/tan(x)) returns atan(1/x).
f = x^2+y;
finverse(f,y) returns y - x^2.
finverse(f) returns (x - y)^(1/2) and a warning that the
inverse is not unique.

英语翻译FINVERSE Functional inverse.g = FINVERSE(f) returns the functional inverse of f.f is a scalar sym representing a function of exactly one symbolic variable,say 'x'.Then g is a scalar symthat satisfies g(f(x)) = x.g = FINVERSE(f,v) uses the
这是matlab里面求逆函数的函数.
主要意思就是 g = FINVERSE(f) 是求f的逆函数.f是一个可以由一个变量x来表示,那么g就是g[f(x)]=x的量.
g = FINVERSE(f,v) 使用了符号变量v,这里v是一个独立变量.g则是一个满足g[f(v)]=v的量.在f包含超过1个符号变量时可以使用这个公式.如果g不存在或者f是个多项式,系统会给出一个解释.
例子：
求1/tan(x)的逆函数：
finverse（1/tan（x）） %直接输入这个式子,就是在求1/tan(x)的逆函数.
ans=atan（x） %求出上面式子的答案
求f=x^2+y的逆函数：
>> syms x y; %定义变量
>> f=x^2+y; %定义f函数
>> finverse(f,y) %求逆
ans =
-x^2+y
>> finverse(f) %直接输入finverse（f）求逆
Warning:finverse(x^2+y) is not unique.%给出警告,finverse（x^2+y）不唯一
> In sym.finverse at 43
ans = %给出答案
(-y+x)^(1/2)