daily interest rate: 0.05/365
principal: $10,000
the value of the investment depends on the time. if you want the value of the investment in the future (assuming the 10,000 was deposited today, you would use the compound interest formula)
value after "t" days = 10,000 * ( (1 + 0.05/365)^t
"5% annual interest" is not the best way to phrase it. APR is the common standard.
The nominal (?) rate would be less than 5%, so that when interest is compounded daily you end up earning [ 10,000 x 5% = $500 ] for the year.
Value depends on time; and purchasing power is also related to the rate of inflation.
