Describe and correct the error a student made in writing an exponential function
starting value = 6
constant ratio = 1/3

f(x) = 6(1/3)^x
f(x) = 2^x

we CANNOT DIVIDE 3 with 6.

Step-by-step explanation:

Here,as given in the question:

Starting value = 6

Constant ratio = 1/3

Now, exponential function is obtained by the product of starting value and the constant ratio repeatedly.

⇒ f(x) = (Starting value) x (ratio)... x times

Now, we CANNOT DIVIDE 3 with 6 as it is in the power of x.

Hence, and

f^-1 (-15) = -6

f^-1(4) + f(9)  = 0

Step-by-step explanation:

f^-1 (-15) =

Look where the output is -15 and  find the x value ( x=-6)

Since where are using the inverse function, the input becomes the output and  the output  and the output becomes the input

f^-1 (-15) = -6

f^-1 (4) = -11  (inverse function)

f(9) = 11  ( regular function)

f^-1(4) + f(9) = -11+11 = 0