45-30a+5a^2
5а^2-30а+45=0
а^2-6а+9=0
(а-3)^2=0
45-30a+5a^2=5(а-3)^2=5(а-3)(а-3)
Решение
<span>(2x-1)/(2x+0 + (2x+0/(1-2) = 8/(1-4x2)
ОДЗ: 1 - 4x^2 </span>≠ 0
<span> 4x^2 </span>≠ 1
<span>x </span>≠ - 1/2; x ≠ 1/2<span>
</span>- (2x-1)*(2x-1) + (2x+1)*(2x+1)) - 8 = 0
-(4x^2 -4x +1) +(4x^2 + 4x + 1) - 8 = 0
-4x^2 + 4x - 1 + 4x^2 + 4x + 1 - 8 = 0
8x - 8 = 0
8x = 8
x = 1
Ответ: х = 1
Sin(x) + sin(2x) + sin(3x) = cos(x) + cos(2x) + cos(3x)
<span>sin(2x) + sin(2x – x) + sin(2x + x) = cos(2x) + cos(2x – x) + cos(2x + x) </span>
<span>sin(2x) + sin(2x)·cos(x) – cos(2x)·sin(x) + sin(2x)·cos(x) + cos(2x)·sin(x) = </span>
<span>= cos(2x) + cos(2x)·cos(x) + sin(2x)·sin(x) + cos(2x)·cos(x) – sin(2x)·sin(x) </span>
<span>sin(2x) + 2·sin(2x)·cos(x) = cos(2x) + 2·cos(2x)·cos(x) </span>
<span>sin(2x)·[1 + 2·cos(x)] = cos(2x)·[1 + 2·cos(x)] </span>
<span>[sin(2x) – cos(2x)]·[1 + 2·cos(x)] = 0
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