У=-1,5*(-4)^2 y=-24
у=-1,5*(-2)^2 y=-6 !!!
<span>Sin^2(3pi/2-y)+sin^2(3pi+y)+2tg(5pi/2-y)×tg (3pi+y)
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Решение
Вычислить Sin²(3π/2-y)+sin²(3π+y)+2tg(5π/2-y)*tg (3π+y) .
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Применяя формулы приведения ,получаем :
Sin²(3π/2-y)+sin²(3π+y)+2tg(5π/2-y)*tg (3π+y)= (cos²y +sin²y)+ 2ctqy*tqy =1 +2*`1 =3.
ответ : 3.
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sin (3π<span>/2-y)) = -cosy
</span>sin(3π +y ) =sin( (2π+(π +y ) )=sin(π<span> +y </span><span>) = </span> -siny
tg(5π/2-y) =tg((2π +(π<span>/2-y) )</span> =tq(π/2-y) =ctqy
tq(3π +y ) =tq( (2π+(π +y ) ) =tq(π<span> +y ) =tqy</span>
<span> -15a-b-2+14a=-a-b-2</span>
Возведем обе части в квадрат
![(5x-4)^2=(8-5x)^2 \\25x^2-40x+16=25x^2-80x+64 \\16-40x=64-80x \\80x-40x=64-16 \\40x=48 \\10x=12 \\x=1,2](https://tex.z-dn.net/?f=%285x-4%29%5E2%3D%288-5x%29%5E2%0A%5C%5C25x%5E2-40x%2B16%3D25x%5E2-80x%2B64%0A%5C%5C16-40x%3D64-80x%0A%5C%5C80x-40x%3D64-16%0A%5C%5C40x%3D48%0A%5C%5C10x%3D12%0A%5C%5Cx%3D1%2C2)
Ответ: x=1,2