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

Van = facebook.com/LearningCalculus;

f(x):=(2-sec(x)^2)/(sec(x)^2);

g(x):=(csc(x)^2-2)/csc(x)^2;

left:ratsimp(subst(1-sin(x)^2,cos(x)^2,trigsimp(f(x))));

right:trigsimp(g(x));

is(equal(left,right));