Question

Which function represents a vertical stretch of an exponential function?
a. f(x)= 3(1/2)^x
b. f(x)= 1/2 (3)^x
c. f(x)= (3)^2x
d. f(x)= 3^(1/2x)

Answer 1

Here: http://www.biology.arizona.edu/biomath/tutorials/exponential/Graphing2.html

Answer 2

if f(x) is the function then af(x) (where a is greater than 1) will stretch it vertically with factor a.