kill(all)$
load(ntrig)$
load(atrig1)$

van=facebook.com/LearningCalculus$

f(x):= 2*cos(%pi/9) = sqrt((3*x-1)/(x-1));

X:sqrt(3)*cot(%pi/9);

f(X);

solve(f(x),x);

'is(equal((4*cos(%pi/9)^2-1)/(4*cos(%pi/9)^2-3)-sqrt(3)*cot(%pi/9),0));

STUCK! 

float(f(X));

float(X);