Final answer:
The function representing a vertical stretch with a factor of 2 of the function f(x) = 8^x is g(x) = 2 × 8^x.
Step-by-step explanation:
The student has asked which function represents a transformation of f(x) = 8^x by a vertical stretch with a factor of 2. A vertical stretch is achieved by multiplying the original function by the stretch factor. Therefore, the transformed function would be g(x) = 2 × f(x), which means g(x) = 2 × 8^x. This function represents the original function stretched vertically by a factor of 2.