Unable to find explicit solution

I am trying to find the value of tau when differentiation of f is zero.

syms tau;
mu_B = 1;
theta_BH = 1;
mu_H = 1;
theta_HB = 1;
f = (1/mu_B)*(2^(theta_BH/tau)-1)+(1/mu_H)*(2^(theta_HB/(1-tau))-1)*((1-tau)/tau);
k=diff(f);
solve(k==0);

Warning: Unable to find explicit solution. For options, see help.

and ans is 0x1 sym.

Can anybody tell me what is wrong in this procedure?

[David Goodmanson]

Hi Souvik. probably there is nothing 'wrong' and expression is just too complicated to have an explicit solution. Hey, it happens.

[SOUVIK MITRA]

Thanks. So, is there any way to find the value of tau when differentiation of f is zero?

Answer 1

[Walter Roberson]

vpasolve(k==0, 0.5)

The starting guess can be anything from about 1e-3 upwards.

There are a minimum of 3 different roots of the equation:

0.6278431457
0.02697246510 + 0.2177554874i
0.02697246510 - 0.2177554874i

[SOUVIK MITRA]

thanks