The correct option is C 1
Given : cos−1(4x3−12x2+11x−52)=π3
⇒4x3−12x2+11x−52=cosπ3
⇒4x3−12x2+11x−52=12
⇒4x3−12x2+11x−3=0
By observation, x=1 satisfied above equation. Hence, (x−1) must be a factor.
⇒(x−1)(4x2−8x+3)=0
⇒(x−1)(2x−3)(2x−1)=0
⇒x=1,32,12
∴ Only one integral solution.