1. The problem statement, all variables and given/known data Problem statement is underlined. Having problems to prove this. 2. Relevant equations F(x) = ∫ f(x) dx Question relating to cumulative distributive function. Part ii requiring to relate cumulative distributive function to probability density function. 3. The attempt at a solution Why I'm stuck => (4x³ - 4x² - 39x - 36) ≠ (3 + 2x)²(4 - x) (3 + 2x)²(4 - x) = (-4x³) - 4x² - 39x + 36 Stuck after that as the positive and negative signs seems swapped. Checked again and nothing seems to change. Is this due to a faulty question or I'm missing out something vital?