Consider the expression 12x4−48x2+36.
(i) Extract the greatest common factor (GCF) and write the simplified expression.
(ii) Factor the resulting quadratic expression completely.
(iii) Hence, obtain the complete factorisation of 12x4−48x2+36.
(iv) Using the factorised form, solve the equation 12x4−48x2+36=0, clearly listing all real roots.