There is a question 4.4 in the BPP book, page 271: Henryted has 12% irredeemable bonds in issue with a nominal value of $100. The market price is $95 ex interest. Calculate the cost of capital if interest is paid half-yearly. Answer: If interest is 12% annually, therefore 6% is payable half-yearly. Cost of loan capital = (1+(6/95) )²-1 = 13% I can’t work out why it’s been calculated this way if the formula for irredeemable debt is Kd=i/Po ? Where do the 1s come from and the square root? Is there anyone who would be able to help? Many thanks, Ewa