interest rate nightmares

Hi everyone, Below is a very simple question that i can’t really understand :

if i say a bond with a coupon of 6% every 6 month on the nominal.

So do you compute :

  • nominal * 0,06 * 0,5 - nominal * 1,06^0,5 - nominal*e^(0,5*0,06) I never know (especially between the first both) Thanks for the tips

The semiannual coupon is 6% × ½ = 3%.