Which Rydberg Equation Do I Use?

[505900922]

I am confused as to why we are given two Rydberg equations.

There is En = -(RH)/(n^2)

And there is v=R((1/n^2)+(1/n^2))

When do we use each one? And with what value of R?

I thought we had to use the first one with hydrogen, but then I saw an example where they used the second one with hydrogen..?

Let me know!

Thanks

[905994971]

The equations solve for different things depending on what the question is asking. The first solves for the Energy of the principle quantum number, but the second can be used to solve for either the final or initial n value. We are also given the Rydberg number on the equation sheet.

R = 3.28984 × 1015 Hz