Y`=(12(3x+1)²*3*(4-4,5x)+4,5*4(3x+1)³)/(4-4,5x)²=
=18(3x+1)²(8-9x+3x+1)/(4-4,5x)²=54(3x+1)²(3-2x)/(4-4,5x)²=0
3x+1=0⇒x=-1/3
3-2x=0⇒x=1,5
+ + -
--------------------(-1/3)--------------(1,5)-------------------
возр возр max убыв
ymax=y(1,5)=4*166,375/(-2,75)=-242
y(0)=4*1/4=1 наиб
y(1,5)=-242
y(5)=4*4096/(-18,5)=-885 115/185=-885 23/37 наим