Plz give an example of a function which is surjective but not injective

Question

anonymous · Answer

$$\mathbb{R} \rightarrow  \mathbb{R} $$
defined by
$$ f(x) x^3-3x$$

anonymous · Answer

For every Y in that function there is an X, therefore it's surjective. However not every value of Y has a unique solution for X so it's not injective.

goformit100 · Answer

A warm Welcome to OpenStudy. I can help guide you through this useful site. You can ask your questions to me or you can message me. Please use the chat for off topic questions. Remember to give the person who helped you a medal by clicking on "Best Answer". We follow a code of conduct, ( http://openstudy.com/code-of-conduct ). Please take a moment to read it.