Б
tgx+1/tgx=5/2
2tg²x-5tgx+2=0,tgx≠0
tgx=a
2a²-5a+2=0
D=25-16=9
a1=(5-3)/4=0,5⇒tgx=0,5⇒x=arctg0,5+πk,k∈z
a2=(5+3)/4=2⇒tgx=2⇒a=arctg2+πn,n∈z
г
4sin2xcos2x-3sin²2x-sin²2x-cos²2x=0/cos²2x
4tg²2x-7tg2x+1=0
(2tg2x-1)²=0
2tg2x=1
tg2x=0,5⇒tg2x=0,5⇒2x=arctg0,5+πk,k∈z⇒x=0,5arctg0,5+πk/2,k∈z