let-Z-N-0-f-Z-Z-Z-f-m-n-m-n-m-n-1-2-m-prove-that-f-is-a-one-to-one-function-and-also-an-onto-function-

Question Number 67055 by Tony Lin last updated on 22/Aug/19

l e t Z_{+} = N \cup {0}, f : Z_{+} \times Z_{+} \to Z_{+}

f (m, n) = \frac{(m + n) (m + n + 1)}{2} + m

p r o v e t h a t f i s a o n e - t o - o n e f u n c t i o n

a n d a l s o a n o n t o f u n c t i o n