# Math Help - homotopy

1. ## homotopy

If $dimM=m, show that every map(maybe continuous) $M^m \to S^p$ is homotopic to a constant.

This is the problem 5 in chap8. of 'topology from the differentiable viewpoint(Milnor)'.

I proved it when the map is not onto. But I think it can be onto.

2. Originally Posted by Stiger
If $dimM=m, show that every map(maybe continuous) $M^m \to S^p$ is homotopic to a constant.

This is the problem 5 in chap8. of 'topology from the differentiable viewpoint(Milnor)'.

I proved it when the map is not onto. But I think it can be onto.
Is this topological dimension or dimensionality as a manifold? Is $S^p=\mathbb{S}^p=\left\{\bold{x}\in\mathbb{R}^{p-1}:\|\bold{x}\|=1\right\}$?
Is this topological dimension or dimensionality as a manifold? Is $S^p=\mathbb{S}^p=\left\{\bold{x}\in\mathbb{R}^{p-1}:\|\bold{x}\|=1\right\}$?