f(x) = (x^2 - 2)^4 * √(x^2 + 1)
u(x) = (x^2 - 2)^4
u'(x) = 4 * (x^2 - 2)^3 * 2x = 8x * (x^2 - 2)^3
v(x) = √(x^2 + 1) = (x^2 + 1)^{1/2}
v'(x) = 1/2 * (x^2 + 1)^{-1/2} * 2x = x / √(x^2 + 1)
f'(x) = u'(x) * v(x) + u(x) * v'(x)
f'(x) = 8x * (x^2 - 2)^3 * √(x^2 + 1) + (x^2 - 2)^4 * x / √(x^2 + 1)
f'(x) = (8x * (x^2 - 2)^3 * (x^2 + 1) + (x^2 - 2)^4 * x) / √(x^2 + 1)
f'(x) = x * (x^2 - 2)^3 * (8 * (x^2 + 1) + (x^2 - 2)) / √(x^2 + 1)
f'(x) = x * (x^2 - 2)^3 * (9·x^2 + 6) / √(x^2 + 1)