Question

How do you find the domain and range of `y=2^(-x)`?

Answer 1

Domain: `x in RR`
Range: `{y|0<=y}`

Explanation:

The function is defined for all real numbers, so the domain is:
`{x inRR}`

Since the value of any exponential with a positive base can never be `0`, and the function goes to positive infinity, we can using the fact that it is continuous on this interval conclude that the range must be:
`{y|0<=y}`