<span>6sin ^ 2x-4sin2x +1 = 0
6sin ^ 2x-8sinxcosx + (sin^2x+cos^2x) = 0
7sin ^ 2x-8sinxcosx + соs^2x = 0 - delim na cos^2x
7tg^2x-8tgx+1=0
Замена: tgx=a
7a^2-8a+1=0
a1=1;a2=1/7
Reshaem 2 uravneniya:
1)tgx=1
x=arctg1+Pin=Pi/4+Pin;
2)tgx=1/7
x=arctg1/7+Pin; (n принадлежит Z)
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5Y = 5Y
( 4X + 1)^2 = ( X + 4)^2
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16X^2 + 8X + 1 = X^2 + 8X + 16
16X^2 - X^2 + 8X - 8X = 16 - 1
15X^2 = 15
X^2 = 1
X1 = 1
X2 = - 1
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5Y = X^2 + 8X + 16
5Y = 1 + 8 + 16 = 25
Y1 = 5
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5Y = 1 - 8 + 16 = 9
Y2= 9/5 = 1,8
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Ответ ( 1 ; 5 ) ; ( - 1 ; 1,8 )
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