Sunday, November 11, 2012

Find the solution of the exponential equation , correct to four decimal places. e^(-4x) = 6

We'll recall the principle
that:


e^a = b <=> a = ln
b


For the given equation, we'll take logarithms both
sides:


ln e^(-4x) = ln 6


We'll apply
the power property of logarithms:


ln e^a = a*ln
e


-4x*ln e = ln 6


But ln e =
1.


-4x = ln 6


We'll divide by -4 both
sides:


x = -ln 6/4


We'll get the
calculator to find ln 6 = 1.7917


x =
-1.7917/4


The solution of x, rounded to four decimal places,
is:


x = -0.4479

No comments:

Post a Comment