cosx = tgx;
cosx = sin x/cos x;
cosx ≠0;x≠π/2+πn n∈Z;
cos²x = sinx
-1+sin²x+sinх=0;
sinх=(-1±√(1+4)/2=sinх=(-1±√5)/2:
sinх=(-1-√5)/2; ∅; т.к. IsinхI≤1
sinх=(-1+√5)/2;
х=(-1)ⁿarcsin((-1+√5)/2) +πn; n∈Z
cosx = tgx;
cosx = sin x/cos x;
cosx ≠0;x≠π/2+πn n∈Z;
cos²x = sinx
-1+sin²x+sinх=0;
sinх=(-1±√(1+4)/2=sinх=(-1±√5)/2:
sinх=(-1-√5)/2; ∅; т.к. IsinхI≤1
sinх=(-1+√5)/2;
х=(-1)ⁿarcsin((-1+√5)/2) +πn; n∈Z