f(x)=(x-4)/(x²-12)f`(x)=[1*(x²-12)-2x*(x-4)]/(x²-12)²=(x²-12-2x²+8x)/(x²-12)²==(-x²+8x-12)/(x²-12)²=0x²-8x+12=0x1+x2=8 U x1*x2=12x1=2 U x2=6 _ + _------------------(2)---------------(6)-------------------- min maxymin=y(2)=-2/(-8)=0,25ymax=y(6)=2/24=1/12(2;0,25);(6;1/12)