5sin^x-14sinxcosx-3cos^x=0

Question

5sin^x-14sinxcosx-3cos^x=0

Comments

sin^x ?? cos^x??

Answer 1

Разделим на cos²x
5tg²x-14tgx-3=0
tgx=a
5a²-14a-3=0
D=196+60=256
a1=(14-16)/10=-0,2⇒tgx=-0,2⇒x=-arctg0,2+πn,n∈z
a2=(14+16)/10=3⇒tgx=3⇒x=arctg3_πk,k∈z

Comments

спасибо огромное.