How to determine the value?

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Power(2,a) = 1,
Does anyone have any suggestions on how to determine the value of a?
Thank for any suggestions
Eric
 
The answer to your immediate question is 0 but I guess that's just indicative
of a more general question.

How about using Solver
Put this in a cell

=2^A1

and solve for that cell to the value you know by changing A1

Mike
 
Power(2,a) = 1,
Does anyone have any suggestions on how to determine the value of a?
Click to expand...

More generally, if power(b,x) = n, then x = log(n) / log(b). But
beware of inaccuracies introduced by the computational error that is
inherent in computer arithmetic. Always check to see if power(b,x)
truly is n.

PS: You can replace power(2,a) with 2^a. One less (nested) function.
 
Or use some algebra:

=Power(2,a)
is the same as
2^a (2 raised to the power of a

The equality to start
2^a = 1
taking the natural log of both sides:
ln(2^a) = ln(1)
the left hand side becomes: a*ln(2)
the right hand side becomes 0
so
a*ln(2) = 0
divide both sides by ln(2)
a = 0/ln(2)
or
a = 0

=====
So if you had
=power(2,a) = x
you could do the same thing
2^a = 1
taking the natural log of both sides:
ln(2^a) = ln(x)
the left hand side becomes: a*ln(2)
so
a*ln(2) = ln(x)
divide both sides by ln(2)
a = ln(x)/ln(2)
 
Thank everyone for suggestions
Eric

Dave Peterson said:
Or use some algebra:

=Power(2,a)
is the same as
2^a (2 raised to the power of a

The equality to start
2^a = 1
taking the natural log of both sides:
ln(2^a) = ln(1)
the left hand side becomes: a*ln(2)
the right hand side becomes 0
so
a*ln(2) = 0
divide both sides by ln(2)
a = 0/ln(2)
or
a = 0

=====
So if you had
=power(2,a) = x
you could do the same thing
2^a = 1
taking the natural log of both sides:
ln(2^a) = ln(x)
the left hand side becomes: a*ln(2)
so
a*ln(2) = ln(x)
divide both sides by ln(2)
a = ln(x)/ln(2)
Click to expand...
 
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