4b(b² - 2b + 3) = 4b³ - 8b² + 12b
1
8x²-160x+800-11x²-110x-275+3x²+170x-1600=0
-100x=1075
x=-10,75
2
40+20x+2,5x²+175-7x²-295+4,5x²=0
20x=80
x=4
См фото
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(3-4cos2a+2cos²2a-1)/(3+4cos2a+2cos²2a-1)=
=(2cos²2a-4cos2a+2)/2cos²2a+4cos2a+2)=
=2(cos²2a-2cos2a+1)/2(cos²2a+2cos2a+1)=(cos2a-1)²/(cos2²+1)²=
=(-2sin²a)²/(2cos²a)²=4sin^4a/4cos^4a=tg^4a