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Continuous Interest

The basis for continuous compound interest. See the following example to know the basis for continuous interest.

Example 1.
Suppose $1,000 is deposited in a savings account that earns compounded interest at a rate of 10% per year. How much will be in the account after 1 year if interest is compounded:
(a) Yearly
(b) Semi-annually
(c) Quarterly
(d) Monthly
(e) Weekly
(f) Daily
(g) Hourly
(h) Every minute

Solution:
(a) yearly
    A = C[1 + hih(t)]
      = 1000[1 + (1)(0.1)]
      = $1100
Answer

(b) Semi-annually
    A = C[1 + hih(t)]2
      = 1000[1 + (1/2)(0.1)]2
      = $1102.5
Answer

(c) Quarterly
    A = C[1 + hih(t)]4
      = 1000[1 + (1/4)(0.1)]4
      = $1103.81
Answer

(d) Monthly
    A = C[1 + hih(t)]12
      = 1000[1 + (1/12)(0.1)]12
      = $1104.7
Answer

(e) Weekly
    A = C[1 + hih(t)]52
      = 1000[1 + (1/52)(0.1)]52
      = $1105.06
Answer

(f) Daily
    A = C[1 + hih(t)]365
      = 1000[1 + (1/365)(0.1)]365
      = $1105.155
Answer

(g) Hourly
    A = C[1 + hih(t)]8760
      = 1000[1 + (1/8760)(0.1)]8760
      = $1105.17
Answer

(h) Every minute
    A = C[1 + hih(t)]525600
      = 1000[1 + (1/525600)(0.1)]525600
      = $1105.1709
Answer

In the above example, note that as h goes smaller and smaller (daily, hourly every minute etc.) the value of accumulated amount takes a limiting value.