undefined?

The expression would be undefined when the denominator equals zero (since you can't divide by zero).

So to solve, we take the denominator (2n -1) and set it equal to 0.

2n - 1 = 0

Solve for n:

2n = 1

n = 0.5

The expression is undefined where n = 0.5

Hope that helps! Please vote if it did :)