/sci/ - Science & Math

>>15567074
>I go to smoke
That's bad for you anon. Think about your long term health.

>>15414382
>How do I check if this is surjective / injective or not?
It's not surjective.
As you've pointed out, [math]f(0) = 0, f(1) = 3, f(2) = 4[/math]. If [math]n > 2[/math] then [math]|f(n)| = \left| (-1)^n 2n + \dfrac{(-1)^n - 1}{2} \right| \geq 2n - 1 > 3[/math], so [math]2[/math] isn't in the image.

I'm honestly not sure if you were supposed to figure this out or if there's a mistake in the formula.