1. y=2e^-x -3
2. y=2sin(3x+pi) - 1
3. y= {sqrt(-x) -4 < x < 0
{sqrt(x) 0 < x < 4
domain is asking for allowable x-values and range asks for resulting y-values, but i'm not sure how to do it for these.
ok, here is the algebra thought process involved for your first function ...
what is the domain and range of the parent function ?
what transformation occurs to if the sign of x is changed? how does that transformation affect the domain and range?
how does the transformation of multiplying by affect the domain and range?
finally, how does the final transformation of subtracting from affect the domain and range?