Range of a function without graph

[Brosip]

Homework Statement

Determine the range of each function without graphing it

(a) -(y-2)=4^x-1

(b) y= 3(0.8)^-x - 5

The Attempt at a Solution

I know it may be easy and all, but i was at a doctors appointment when we learned how to do this

 

[e^(i Pi)+1=0]

Off the top of my head - find the inverse and determine its domaine.

 

[HallsofIvy]

Homework Statement

Determine the range of each function without graphing it

(a) -(y-2)=4^x-1

-y+ 2= 4^{x- 1}
-y= 4^{x- 1}- 2
y= 2- 4^{x- 1}

Now if you know that the range of "a^x", for any number a (other that 1 or 0) is (0, infinity), the range of this function should be easy.

(b) y= 3(0.8)^-x - 5[/sup]

Same thing.

The Attempt at a Solution

I know it may be easy and all, but i was at a doctors appointment when we learned how to do this