Question

matlab中用solve函数求方程解，结果是个表达式，然后我带入参数的值，用subs求的结果怎么有很多个？？

syms f x T;
A=solve('(f/log(0.2))*(0.9)^x=num2str(T)','x');
f=960;
T=0.001;
subs(A)

Answer 1

syms f x T;
%A=solve('(f/log(0.2))*(0.9)^x=num2str(T)','x');
A=solve('(f/log(0.2))*(0.9)^x=T','x')
f=960;
T=0.001;
subs(A)
A =
-9.4912215810299030260099326864872*log(-1.6094379124341003746007593332262*T/f)
ans =
1.2622e+002 -2.9818e+001i

% 如果不需要虚根
>>real(subs(A))
ans =
126.2219