A) tg^2x-6tgx+5=0 б) tg^2x-2tgx-3=0

А)tgx-a
a^2-6a+5=0
D=36-4*5=16
a1=6+4/2=5
a2=6-4/2=1
tgx=5
x=arctg5+Пn,n=z
tgx=1
x=П/4+Пn, n=z
2)tgx=a
D=4+12=16
a1=2+4/2=3
a2=2-4/2=-1
tgx=3
x=arctg3+Пn,n=z
tgx=-1
x=-П/4+Пn,n=z