Sin2х+1=0 Sin2х+2cos2х=0

Question

Sin2х+1=0 Sin2х+2cos2х=0

Answer 1

1) sin2x+1=0

sin2x=-1

2x=-pi/2+2*pi*n

x=-pi/4+pi*n

 

2)  sin2x+2cos2x=0

Разделим обе части на cos(2x)

sin2x/cos2x+2*cos2x/cos2x=0

tg2x+2=0

tg2x=-2

2x=arctg(-2)+pi*n

x=arctg(-2)/2+pi*n/2