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I was doing some problems , but I don“t know how to prove 2 of them Dx , that are about homeomorphism. I have to prove that $$ R^{n + 1} - \left\{ 0 \right\} \cong S^n \times\,R $$ where R denotes the real numbers all of this with the usual topology of $R^n$

For every $c>0$ $ \left\{ {\left( {x,y,z} \right) \in R^3 :x^2 + y^2 - z^2 = c} \right\} \cong S^1 \,\times\,R $ I think that it will be useful to use the last problem :/

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