What is f(x) = int x-xsec(x/2) dxf(x)=xxsec(x2)dx if f((7pi)/4) = 0 f(7π4)=0?

1 Answer
Nov 23, 2016

Because the indefinite integral involves the imaginary valued polylogarithmic function, I believe that there is an error in the question.

Explanation:

Wolfram Alpha gives the solution to the indefinite integral as

4i(Li_2(-ie^((ix)/2)) - Li_2(ie^((ix)/2))) +x^2/2-2x(ln(1-ie^((ix)/2)) - ln(1+ie^((ix)/2))) +C4i(Li2(ieix2)Li2(ieix2))+x222x(ln(1ieix2)ln(1+ieix2))+C

Now substitute (7pi)/47π4 for xx, set equal to 00 and solve for CC.