go语言计算债券资本成本

如题:

某公司5年前发行了面值为1000元、利率为10%、期限为15年的长期债券，每年付息一次，刚支付上年利息，目前市价为950元，公司所得税税率为25%，则该公司债务成本是（　） (题目摘自中华会计网校,如有侵权行为,请告知删除)文章源自懂站帝-http://www.sfdkj.com/19185.html

A: 11.14% B:10.86% C:8.14% D:8.36%文章源自懂站帝-http://www.sfdkj.com/19185.html

1,计算复利现值函数:文章源自懂站帝-http://www.sfdkj.com/19185.html

func Pv( fv float64, year int, cost float64) ( pv float64) {文章源自懂站帝-http://www.sfdkj.com/19185.html

pv = fv文章源自懂站帝-http://www.sfdkj.com/19185.html

for i := 0; i < year; i++ {文章源自懂站帝-http://www.sfdkj.com/19185.html

pv /= 1 + cost文章源自懂站帝-http://www.sfdkj.com/19185.html

}文章源自懂站帝-http://www.sfdkj.com/19185.html

return文章源自懂站帝-http://www.sfdkj.com/19185.html

}文章源自懂站帝-http://www.sfdkj.com/19185.html

2,计算年金现值函数:文章源自懂站帝-http://www.sfdkj.com/19185.html

func PvOfAnnuity( parValue float64, interestRate float64, year int, cost float64) (pvOfAnnuity float64) {文章源自懂站帝-http://www.sfdkj.com/19185.html

annuity := parValue * interestRate文章源自懂站帝-http://www.sfdkj.com/19185.html

pvOfAnnuity = Pv( parValue, year, cost )文章源自懂站帝-http://www.sfdkj.com/19185.html

for i := 1; i <= year; i++ {文章源自懂站帝-http://www.sfdkj.com/19185.html

pvOfAnnuity += Pv( annuity, i, cost)文章源自懂站帝-http://www.sfdkj.com/19185.html

}文章源自懂站帝-http://www.sfdkj.com/19185.html

return文章源自懂站帝-http://www.sfdkj.com/19185.html

}文章源自懂站帝-http://www.sfdkj.com/19185.html

然后穷举法计算cost,为减少计算时间,默认从最小的0.08开始文章源自懂站帝-http://www.sfdkj.com/19185.html

func main(){

var (

price float64 = 950

parValue float64 = 1000

interestRate float64 = 0.1

cost float64 = 0.08

year int = 10

)

for {

cost += 0.00001 //精确到十万分之1

if PvOfAnnuity( parValue, interestRate, year, cost) >= price && PvOfAnnuity( parValue, interestRate, year, cost+0.00001) < price {

fmt.Printf("%.2f%%", 100*cost*0.75)

break

}

}

}

打印结果显示为 8.13%

答案选C. (电脑计算结果比插值法更精确)