1+ tg ^2 x = 1/ cos^2 x
1+7 = 1/ 50cos^ x
8= 1/ 50 cos^ x
8* 50 cos^2 x =1
400 cos^ x =1
cos^2 x = 1/400
cosx =1/20
cos x = 0.05
2cos(п/3-x)=1
cos(п/3-x)=1/2
cos(x-п/3)=1/2
x-п/3 = +-arccos(1/2)+2пk
x-п/3=+-п/3+2пk
x=2п/3+2пk; x=2пk
<span>2 log_0,5( 5)-2 log_0.5(10)=
log_0.5(10)-log_0.5(20)=
log_0.5(10/20)=
log_0.5(1/2)=
log_1/2(1/2)=1</span>