Tg x - tg (7π/2 - x) = 1

tgx-tg(7π/2-x)=1 tgx-ctgx=1 tgx-1/tgx=1 tg²x-tgx-1=0,tgx≠0 tgx=a a²-a-1=0 D=1+4=5 a1=(1-√5)/2⇒tgx=(1-√5)/2⇒x=arctg(1-√5)/2+πn,n∈z a2=(1+√5)/2⇒tgx=(1+√5)/2⇒x=arctg(1+√5)/2+πn,n∈z