"Conversion to logical from sym is not possible" arising in bisection method

The following is my code. i want to calculate gss here. problem arising in " if f(gss1)*f(gss2) < 0 ". In command window " Conversion to logical from sym is not possible. " this type of comment is showing. Want some help to do this. thanks in advance.

syms gss

m = 4.7542;

gsms = 11.299 ;

gomo = 5.696 ;

gpmp = 4.656 ;

m1 = (m - gss);

p = 0 ;

k = (3 * p * pi^2 / 2)^(1/3) ;

k1 = sqrt(k^2 + m1^2);

goo = gomo * p ;

moo = goo * p/2 ;

f(gss) = (gss - (gsms * m1 * (k1 - m1^2/2 *log((k1+k)/m1))/pi^2 )) ;

pretty(f);

gss1 = input('gss1=');

gss2 = input('gss2=');

if f(gss1)*f(gss2) < 0

gss = (gss1+gss2)/2 ;

n = 0;

while abs (f(gss))> 0.00001

n = n + 1;

gss = (gss1 + gss2)/2;

if f(gss1)*f(gss)< 0

gss2 = gss;

else

gss1 = gss;

end

end

fprint('no root')

end

Answer 1

[Walter Roberson]

fgss = (gss - (gsms * m1 * (k1 - m1^2/2 *log((k1+k)/m1))/pi^2 )) ;
f = matlabFunction(fgss)