Given tan−1(1−α)+tan−1(1−β)=4π
Applying the formula tan−1x+tan−1y=tan−1(1−xyx+y), we get:
1−(1−α)(1−β)(1−α)+(1−β)=tan(4π)=1
2−α−β=1−(1−α−β+αβ)
2−α−β=α+β−αβ
2(α+β)=2+αβ
Given β=3α1, we have αβ=31. Substituting this into the equation:
2(α+β)=2+31
2(α+β)=37
α+β=67
Therefore, 6(α+β)=6×67=7
Answer: 7