Correct answer: (1/5, 0)
The integral of tanⁿ x can be expressed in terms of lower powers of tan x and x, and through integration by parts or reduction formulas, it can be shown that the combination I₄ + I₆ results in a term proportional to tan⁵ x with a coefficient of 1/5, while the x⁵ term does not appear, leading to the ordered pair (1/5, 0).