kill(all)$

van=facebook.com/LearningCalculus$

f(x):=x^2/(2^x^2 - 1)$
g(x):=x^2/(2^x^2 + 1)$

limit(f(x),x,0);

G(x):=diff(g(x),x)$ G(x);

newton(t):=float(subst(t,x,x-G(x)/diff(G(x),x)))$

u:newton(1.3580995750657524100895389138)$

float((atan(((((-g(u))+(log(2))^((-1))))^((-1))*u)))*180/%pi);

float(cos((atan(((((-g(u))+(log(2))^((-1))))^((-1))*u)))));