Could you restate the problem?
. . Your writing raises many questions.
I need help on solving the following equation. . . . . Equation?
∫ (π+t) cos (nt) dt + ∫ (π-t) cos (nt) dt
I don't know if it's clear but its like this:
"Integral of [(pi + t) into cos (nt)] dt + integral of [(pi - t) into cos (nt)] dt."
What does "into" mean?
If the problem is: .
. . why not make one integral?