X ^ 1/2 - 10x ^ 1/4 + 9 = 0
X ^ 1/4 = a ; x ^ 1/2 = a^2
A^2 - 10a + 9 = 0
D = 100 - 36 = 64
V D = 8
A1 = ( 10 + 8 ) : 2 = 9
A2 = ( 10 - 8 ) : 2 = 1
X ^1/2 = a
X ^1/2 = 9 ; x ^ 1/2 = 81 ^ 1/2 ; x = 81
X ^ 1/2 = 1 ; x = 1
Ответ 1 ; 81
Решение задания смотри на фотографии
<span>sinx-sin3x/cosx-cos3x*(1-cos4x)=-2sinxcos2x/2</span>sinxsin2x *2sin²2x=2cos2xsin2x=
=-sin4x
-sin4x=-sin4x
(7sin37°sin53°)/cos164°=
=(7sin37°sin(90°-37°))/cos(90°+74°)=
=(7sin37°cos37°)/-sin74°=
=(7sin37°cos37°)/-sin(2•37°)=
=(7sin37°cos37°)/(-2sin37°cos37°)=
=-7/2