Y=-2/3 x√x+3x {1;9} max и min

Question

Y=-2/3 x√x+3x {1;9} max и min

Answer 1

Y=-2/3*x√x+3x; x∈[1;9]
y⁾=-2/3*2/3*√x+3=-√x+3
-√x+3=0⇒√x=3⇒x=9
9∈[1;9]
y(1)=-2/3+3=2 1/3
y(9)=-2/3*9*3+9=-9
max y=y(1)=2 1/3
min y=y(9)=-9