No. 2x changes x values, the domain, not the range. The range of tan-1(x) is (-pi/2, pi/2) because as x goes to negative infinity, tan-1[/sup](x) goes to -pi/2 and as x goes to infinity, tan-1(x) goes to pi/2.
As x goes to -infinity, what does 2x go to? What does tan-1(2x) go to?
As x goes to infinity, what does 2x go to? What does tan-1(2x) go to?