∫[0,i] zsinzdz
= - ∫[0,i] zd(cosz)
= [-zcosz][0,i] + ∫[0,i] coszdz
= [-zcosz][0,i] + [sinz][0,i]
= [sinz-zcosz][0,i]
= sin(i)-icos(i)-sin0+0cos0
= [e^(i*i)-e^(-i*i)]/(2i) - i*[e^(i*i)+e^(-i*i)]/2
= i*[e^(-1)-e^(1)]/(-2) - i*[e^(-1)+e^(1)]/2
= -i*[e^(-1)-e]/2 - i*[e^(-1)+e]/2
= -i*[e^(-1)-e+e^(-1)+e]/2
= -i*[2e^(-1)]/2
= -i*e^(-1)
= -i/e