Having a little trouble with it:

Is $f(x) = \dfrac{2x}{1+x^2}$ an injective? Why or why not?

If I graph this function, we can see that it is not injective, but how to show that algebraically?

Question

Having a little trouble with it:

Is $f(x) = \dfrac{2x}{1+x^2}$ an injective? Why or why not?

If I graph this function, we can see that it is not injective, but how to show that algebraically?

anonymous · Answer

@ganeshie8 @iGreen @AriPotta

anonymous · Answer

OK, we start with $f(a) = f(b)$

I am stuck at $b+a^2b = a+ab^2$...

I honestly don't know how to show that it is not injective without depending on graph.

zarkon · Answer

what is $$f(1/x)$$

uri · Answer

We can go from there:

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