y=2(3^x)-1 domain, range?

[aisha]

I was given the equation y=2(3^x)-1 and told to state the domain, range, x and y intercepts and asymptotes.

I graphed the eqn and got the x-intercept to =-0.63 and the y-intercept=1
the vertical asymptote is the same as x-intercept so =-0.63 and the horizontal asymptote always equals 0.

If these values are right, then I need to find out the domain and range, but I dont know how. Can someone please help me? :redface:

[dextercioby]

I was given the equation y=2(3^x)-1 and told to state the domain, range, x and y intercepts and asymptotes.
I graphed the eqn and got the x-intercept to =-0.63 and the y-intercept=1
the vertical asymptote is the same as x-intercept so =-0.63 and the horizontal asymptote always equals 0.
If these values are right, then I need to find out the domain and range, but I dont know how. Can someone please help me? :redface:


Me again,...This time i say to review calculations.
Hints:1)Do u agree with me that the domain in the entire real axis and the range the open interval (-1,+infinity)??
2)Use the correct definitions of veritical/horizontal asymptotes.
3) Solve the equations for the intersections correctly.

PS I assumed that your initial function was y=2\cdot 3^{x} -1 .