Find A union B.
A: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}
B: {−2, −1, 1, 4, 7, 11}

Question

Find A union B.
A: {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}
B: {−2, −1, 1, 4, 7, 11}

accidentalaichan · Answer

Oh, I get it. Thanks!
So, {-2, -2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12}?

accidentalaichan · Answer

*-2, -1

psymon · Answer

Am I saying something incorrect?

ankit042 · Answer

NO @Psymon fumbled with Union and intersection ....your previous answer looks correct..just don't repeat the terms

psymon · Answer

Ah, you're right, sorry x_x Mixed them up

psymon · Answer

Reversed the order. Geez, I mess up a lot o.o

accidentalaichan · Answer

It's quite alright. Thanks for helping @ankit042  and @Psymon

anonymous · Answer

$$\bf A \cup B = A+B-(A ∩ B)$$

psymon · Answer

Eh, thanks @AccidentalAiChan x_x I embarrass myself too much on here, though, lol x_x

ankit042 · Answer

Haha It is Ok to make mistakes as far as you learn from them!

anonymous · Answer

@AccidentalAiChan Let's assume that a set $\bf A = {a_1,a_2,a_3}$ and a set $\bf B=a_3,a_4,a_5$. Then the union is:$$\bf A \cup B = A+B-(A ∩ B)=  \left\{ a_1,a_2,a_3 \right\} + \left\{ a_3,a_4,a_5 \right\}-(\left\{ a_3 \right\})$$$$\bf \implies A \cup B = \left\{ a_1,a_2,a_3, a_3,a_4,a_5 \right\}-\left\{ a_3 \right\}=\left\{ a_1,a_2, a_3,a_4,a_5 \right\}$$You must evaluate your problem similarly.

@AccidentalAiChan