作业帮这个Matlab为何会出错?
来源：学生作业帮 编辑：作业帮 分类：综合作业 时间：2024/04/30 02:59:26
这个Matlab为何会出错?
>> [x]=solve('(1/x^0.5)=-2*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)')
Error using ==> mupadmex
Error in MuPAD command:cannot differentiate equation [numeric::fsolve]
Error in ==> sym.sym>sym.mupadmexnout at 2003
out = mupadmex(fcn,args{:});
Error in ==> solve at 76
[symvars,R] = mupadmexnout('mllib::solvefull',eqns,vars);
>> [x]=solve('(1/x^0.5)=-2*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)')
Error using ==> mupadmex
Error in MuPAD command:cannot differentiate equation [numeric::fsolve]
Error in ==> sym.sym>sym.mupadmexnout at 2003
out = mupadmex(fcn,args{:});
Error in ==> solve at 76
[symvars,R] = mupadmexnout('mllib::solvefull',eqns,vars);
这个可能得用求数值解的函数来解,fsolve
solve只能求出精确解
再问： x=fsolve(@(x) (-2)*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)-(1/x^0.5),[-1 1],optimset('Display','off')) ??? Error using ==> mpower Matrix must be square. Error in ==> @(x)(-2)*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)-(1/x^0.5)
solve只能求出精确解
再问： x=fsolve(@(x) (-2)*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)-(1/x^0.5),[-1 1],optimset('Display','off')) ??? Error using ==> mpower Matrix must be square. Error in ==> @(x)(-2)*log10(5.66*10^(-4)/3.7+2.51/8000/x^0.5)-(1/x^0.5)