1= 5.64
2= 2.44+3.16=5.60
2 больше
5tgx-12=0, 13cos-5≠0
tgx=2,4 U cox≠5/13⇒sinx≠12/13⇒tgx≠2,4-решения нет
1) (b(2a-3b)-a(4a-5b))/(a²b²)=(2ab-3b²-4a²+5ab)/(a²b²)= (4a²+7ab-3b²)/a²b²
2) (y(5x²-3y)+6x-2y²)/(x²y²)=(5x²y-3y²+6x-2y²)/(x²y²)=(5x²y-5y²+6x)/(x²y²)
3) ((3(a-b)-48(4-4b)+28/(a-b))/24=(3a-3b-48a+192b+28a-28b)/24=(-17a+161b)/24
F'(x)=x'*sinx+x*(sinx)'=sinx+x*cosx ; f'(π/2)=sin(π/2)+(π/2)*cos(π/2)=1