The graphs below show four functions: Graph A shows function f of x equals 3 multiplied by 3 to the power of x. Graph B shows function f of x equals 9 to the power of x. Graph C shows function f of x equals 3 multiplied by 3 to the power of negative x. Graph D shows function f of x equals 9 to the power of negative x. Which graph best shows the function f(x) = 3(3)−x to represent the rate at which a radioactive substance decays? (1 point)

Answer: graph C

Justitication:

f of x equals 3 multiplied by 3 to the power of negative x means exactly [tex]3 (3^{-x} )[/tex], which is what the question indicates.

So, do not even have to see the graphs, the same statement tells that the graph C is the graph of [tex]3( 3^{-x})[/tex].

It is used to represent the rate at which a radioactive substance decays because the function decays at a factor of (1/3) as x incresases 1 unit.