(i) 2 * 3 = 3 x 2^{2} - 3 = 12 - 3 = 9

Given ; a*b = 3a^{2} - b

b*a = 3b^{2} - a ≠ a*b

Hence not commutative.

(ii) f of (x) = f (f(x)) = f (x^{2} -3x +2)

=(x^{2 }-3x + 2)^{2} - 3 (x^{2} - 3x + 2)

= x^{4 }+ 9x^{2} + 4 - 6x^{3} + 4x^{2} - 12x - 3x^{2} + 9x - 6 +2

= x^{4} - 6x^{3} + 10x^{2} - 3x

f of (1) = 1 - 6 + 10 - 3 = 2