SOLUTION: How do you find the range of y=2^x-1?

Algebra ->  Exponential-and-logarithmic-functions -> SOLUTION: How do you find the range of y=2^x-1?      Log On


   

Question 832505: How do you find the range of y=2^x-1?
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
y=2%5Ex-1
If x = 0, y = 2^0 - 1
y = 1 - 1 = 0
y can take any positive value with the right value for x.
But can y take on any negative value?
For example, if we want y to be -2, what value would
x need to take?
Let's see what happens if x is set to a large negative number, say -10000
y+=+2%5E%28-10000%29+-1+=+1%2F2%5E%2810000%29+-1
It turns out that no matter how large of a negative number we choose,
we cannot produce a value of y that is -1 or less.
So the range is (-1,infiniti)