<span>а) 24-x^2=0
x²=24
x=-2√6 U x=2√6
б) 81x^2=100</span>
x²=100/81
x=-10/9 U x=10/9
<span>(x+4)^2=3x+40
x²+8x+16-3x-40=0
x²+5x-24=0
x1+x2=-5 U x1*x2=-24
x1=-8 U x2=3
x^2+3x/2=x+7/4</span>
x²+3x/2-x-7/4=0
4x²+2x-7=0
D=4+112=116
x1=(-2-2√29)/8=-(1+√29)/4
x2=-(1-√29)/4
Решение
tg(π/4 + a) = [tg(π/) + tga] / [1 - tg(π/4)tga] =
= (1 + tga) / (1 - tga)
cosa = 12/13
sina = √(1 - cos²a) = √(1 - (12/13)²) = √(1 - 144/169) =
= √25/169) = 5/13
tga = sina/cosa = 5/13 : 12/13 = 5/12
tg(π/4 + a) = [1 + (5/12)] / [1 - (5/12)] =
= 17/12 : 7/12 = 17/7 = 2 (3/7)
( 2 - 3Y) / ( Y - 5) = 2Y / ( 5 - Y)
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2 - 3Y = - 2Y
Y = 2
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Ответ под цифрой 1)
А) -∞____+___-18____-___-11____+____14____-____15___+___17___-___+∞
x∈(-∞;-18]∨[-11;14]∨[15;17].
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