Normal bundles in products of spheres (Ex)

Exercise 0.1.

1. For which $<wikitex>; {{beginthm|Exercise}} # For which $k$ does the diagonal embedding $S^k \to S^k \times S^k, \quad x \mapsto (x, x)$ have trivial normal bundle? # For all $k$, find an immersion representing the diagonal homology class $(1, 1) \in H_k(S^k \times S^k)$ with trivial normal bundle. {{endthm}} </wikitex> == References == {{#RefList:}} [[Category:Exercises]] [[Category:Exercises without solution]]k$ does the diagonal embedding $S^k \to S^k \times S^k, \quad x \mapsto (x, x)$ have trivial normal bundle?
2. For all $k$, find an immersion representing the diagonal homology class $(1, 1) \in H_k(S^k \times S^k)$ with trivial normal bundle.