Substituting u=logt with dt=eudu:
f(t)=∫1−cosu1−sinueudu
Express as: 1−cosu1−sinu=21csc2(u/2)−cot(u/2)
Using integration by parts and standard techniques:
f(t)=elogtcot(2logt)+C=tcot(2logt)+C
From f(eπ/2)=−eπ/2:
eπ/2cot(π/4)+C=−eπ/2 → eπ/2+C=−eπ/2 → C=−2eπ/2
For f(eπ/4): f(eπ/4)=eπ/4cot(π/8)−2eπ/2
With cot(π/8)=1+2: α=−1−2