Matlab returns wrong result

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enlightenight 2016-10-11

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评论： enlightenight 2016-10-12

I am trying to calculate an annual return based on the given formula for a homework. I typed this code:

function A = untitled9(R, m, p)
  k = ((1+p)^(m-1))*p
  h = ((1+p)^m)-1
  g = k/h
  A = g.*R 
  s=sprintf('The annual installment for Katja is %.2f', A); 
  disp(s)

for the values R=75000, m=10 and p=0.04; the result should be 8887.5. but matlab insists on returning 8891.17, even though it calculates k, h and g right. (i purposefully coded it that way so I could see if I did something wrong in the initial formula.)

can someone please help me?

edit: it returns the same answer when i manually enter 75000 as the number to multiply g value by.

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Answer 1

Preethi 2016-10-12

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编辑：Preethi 2016-10-12

在 MATLAB Online 中打开

Hi,

the value displayed by Matlab is precise value since it uses g value as 0.118549. if you want 8887.5 then truncate the value of g to 0.1185. (I used a crude method)

   g1 = str2num(sprintf('%.4f',g))
    A = (g1.*R)

when you are displaying in command window it shows 4 characters after decimal(I think its standard method), hence the confusion.

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enlightenight 2016-10-12

oh my god thanks a lot! i spent an embarrassing amount of time on it, trying to figure out where i did a mistake. seriously, you saved my mind before my exam!

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