Question

Is the function p(r) = 6^r + 9^r exponential?

Answer 1

how do we put it in f(t) = ab^t form?

Answer 2

I don't think it can be put in the form: p(r) = a * b^r

If we go by being able to put it in the form a*b^x as the definition of an exponential function, then the given function is not an exponential function.

If having a variable as an exponent makes it an exponential function, then the given function is an exponential function.

What does your textbook / /class notes / teacher say is the definition of an exponential function?