kill(all)$

van = facebook.com/LearningCalculus;

f(x):=sin(x)/(1+sec(x)^2);

g(x):=''(integrate(f(x),x))+C;

S:first(solve(f(x)=g(x),x));

load(ntrig)$ load(atrig1)$

trigsimp(S);

tan(lhs(S))=tan(rhs(S));

inside:(cos(x)^2*sin(x)+cos(x)^3+cos(x))/(cos(x)^2+1);

substitute((1-sin(x)^2),cos(x)^2,inside);

Problem: f(x) = 'integrate(f(x),x)$

     Find all x that satisfy:

Problem;

in_R_from:[-inf,inf];