5.5
y`=√x+(x-9)/2√x=(2x²+x-9)/2√x=0
2x²=x-9=0
D=1+72=73
x1=(-1-√73)/4
x2=(-1+√73)/4
+ _ +
------------------((-1-√73)/4)-----------(-1+√73)/4 )--------
min
5.6
y`=-√x+(6-x)/2√x=(-2x²-x+6)/2√x=0
-2x²-x+6=0
D=1+48=49
x1=(1-7)/(-4)=1,5
x2=(1+7)/(-4)=-2
_ + _
-------------(-2)---------------(1,5)----------------
max