Question

решите уравнение sin^2x + sin2x=1

Answer 1

sin²x+sin2x=1
sin²x+2sinxcosx-1=0
sin²x+2sinxcosx-sin²x-cos²x=0
2sinxcosx-cos²x=0
cosx(2sinx-cosx)=0
1)cosx=0,x=π/2+πk,k-Z
2)2sinx-cosx=0
2sinx=cosx |:cosx
2tgx=1
tgx=1/2
x=arctg1/2+πn,n-Z