搜搜考试网matlab中怎么把积分函数 int 得到的不定积分式代入 solve 函数中进行计算?
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matlab中怎么把积分函数 int 得到的不定积分式代入 solve 函数中进行计算?
例如：
syms r x
fun=int(r*exp(-2*(r/2)^2),r,0,x);
x=solve('fun-0.5','x');
运行将会报错：
Warning:Explicit solution could not be found.
> In solve at 81
但是如果是运行
x=solve('int(r*exp(-2*(r/2)^2)-0.5,r,0,x)','x');
又会报错
Error using ==> solve>getEqns at 182
' int(r*exp(-2*(r/2)^2)-0.5,r,0,x) ' is not a valid expression or equation.
Error in ==> solve at 67
[eqns,vars] = getEqns(varargin{:});
例如：
syms r x
fun=int(r*exp(-2*(r/2)^2),r,0,x);
x=solve('fun-0.5','x');
运行将会报错：
Warning:Explicit solution could not be found.
> In solve at 81
但是如果是运行
x=solve('int(r*exp(-2*(r/2)^2)-0.5,r,0,x)','x');
又会报错
Error using ==> solve>getEqns at 182
' int(r*exp(-2*(r/2)^2)-0.5,r,0,x) ' is not a valid expression or equation.
Error in ==> solve at 67
[eqns,vars] = getEqns(varargin{:});
syms r x
fun=int(r*exp(-2*(r/2)^2),r,0,x);
x=solve(fun-0.5)
x =
2^(1/2)*log(2)^(1/2)
-2^(1/2)*log(2)^(1/2)
fun=int(r*exp(-2*(r/2)^2),r,0,x);
x=solve(fun-0.5)
x =
2^(1/2)*log(2)^(1/2)
-2^(1/2)*log(2)^(1/2)