\ \
The principal amount
.
Amount after
is
.
Formula for continuous compounding:
.
Substitute
,
and
.



Apply ln on each side.
\

Substitute the value of
.

.
The rate of interest
.
The amount is doubled in
years.
The amount
.
Compounded continuously.
\Formula for continuous compounding:
.


Apply ln on each side.
\
Apply power rule of logarithms:
.

Substitute the value of
.

\ \
Substitute
.

.
| Initial investment | \Annual rate | \Time to double | \Amount after years | \
| \
\
| \
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\ \