R={(x,y):x3≤y≤x, 0≤x≤1}
vertical line sx=α splits the area in half
To find: the correct statement about α
x≥x3 on [0,1]: upper y=x, lower y=x3
A=∫01(x−x3)dx=21−41=41
left part=∫0α(x−x3)dx=2α2−4α4=81
4α2−2α4=1 ⇒ 2α4−4α2+1=0 ⇒(3) is true
2u2−4u+1=0⇒u=α2=1±22
α∈(0,1)⇒α2=1−22⇒α≈0.541∈(21,1)
Answer: statements (2) and (3)