Question

1) 2sin2x+3sin²x=0
2) 21sin2x+2sin²x+8=0

Answer 1

4sinxcox+3sin²x=0|:cos^2x
4tgx+3tg^2x=0
tgx=a
3a^2+4a=0
a1=0? a2=-4/3
tgx=0
x=Пn
tgx=-4/3
x=arctg(-4/3)+Пk