An exponential function f(x)=(25)x

contains the point (3,0.064)
. Its corresponding logarithmic function g(x)=log25x
contains the point (a,3)
. What is the value of a?

1 answer

To find the value of \( a \) for the logarithmic function \( g(x) = \log_{25}(x) \) that contains the point \( (a, 3) \), we use the relationship between exponential and logarithmic functions.

Given that \( f(x) = 25^x \) contains the point \( (3, 0.064) \), we can verify this point:

\[ f(3) = 25^3 \]

Calculating \( 25^3 \):

\[ 25^3 = 25 \cdot 25 \cdot 25 = 625 \cdot 25 = 15625 \]

This means the point \( (3, 0.064) \) is incorrect, as \( 25^3 \neq 0.064 \).

Instead, let's check what \( 25^x \) would equal when \( x = 3 \):

\[ f(3) = 25^3 = 15625 \]

Now let's calculate what the logarithmic function \( g(x) = \log_{25}(x) \) looks like for the point \( (a, 3) \):

The point \( (a, 3) \) means:

\[ g(a) = 3 \]

By definition of the logarithm, this translates to:

\[ \log_{25}(a) = 3 \]

To solve for \( a \), we can rewrite this equation in exponential form:

\[ a = 25^3 \]

Now, we calculate \( 25^3 \):

\[ 25^3 = 15625 \]

Thus, the value of \( a \) is:

\[ \boxed{15625} \]