If R→R is is an invertible function such that f(x) and f-1x are symmetric about the line y=-x, then
f(x) is odd
f(x) and f-1x may not be symmetric about the line y=x
f(x) may not be odd
none of these
Since f(x) and f-1x are symmetric about the line y = x.
If α,β lies on y=fx, then -α,-β lies on y=f-1x.
Therefore, -α,-β lies on y=fx.Hence, y=fx is odd.