The correct answer is -15 because the absolute value is 15 but there is a negative outside the absolute value lines making it negative :)
First integrate the entire thing by letting multiplying by 1/2 the entire expression raised to exponent 1/2 - 1. That is,
0.5(1 + x³)^-0.5
Then, multiplying this by the derivative of those inside the parentheses. The final answer would be,
(0.5)((1 + x³)^-0.5)(3x²)
