How can I prove the surjectivity of this function? I know I'm trying to prove that for all y in the range there exists an x in the domain such that $\displaystyle y=x^3$, but I can't think how to go about proving it. Thanks.
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Originally Posted by Greengoblin How can I prove the surjectivity of this function? Does $\displaystyle \sqrt[3]{{y - 5}}$ exist fo every y?
Ah yes thanks. I was trying to show it's onto in order to show that it has an inverse, but I didn't think to try it the other way round.
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