1.вычислить 2cos п/6*sin п/3+√3*tg п/6 2.найдите производную функции y=8-5x^4+7/2x при x=-1

1) cos(π/6) = √3/2
sin(π/3) = √3/2
tg(π/6) = √3/3
2*(√3/2)*(√3/2) + √3*(√3/3) = 2*3/4 + 3/3 = 3/2 + 1 = 2.5
2) y' = -5*4x^3 - 7/(2x^2) = -20x^3 - 3.5/(x^2)
x= -1, y'(-1) = 20 - 3.5 = 16.5