Can someone give me some hints on how to prove the following statement: if [tex] f: S^3 \to S^2, g: S^3 \to S^3[/tex] then [tex]H(f\circ g) = deg~g H(f)[/tex] where H is the Hopf invariant and deg g is the degree of g. I'm pretty clueless on how to start and I don't see how to get the deg to come in since that has to do with 3-d cohomology but the Hopf invariant has to do with 2-d and 4-d cohomology.(adsbygoogle = window.adsbygoogle || []).push({});

Thanks.

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# Hopf invariant

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