2.I.4F

Metric and Topological Spaces
Part IB, 2006

Which of the following subspaces of Euclidean space are connected? Justify your answers (i) {(x,y,z)R3:z2x2y2=1}\left\{(x, y, z) \in \mathbf{R}^{3}: z^{2}-x^{2}-y^{2}=1\right\}; (ii) {(x,y)R2:x2=y2}\left\{(x, y) \in \mathbf{R}^{2}: x^{2}=y^{2}\right\}; (iii) {(x,y,z)R3:z=x2+y2}\left\{(x, y, z) \in \mathbf{R}^{3}: z=x^{2}+y^{2}\right\}.