## itsjustme_lol 2 years ago Operations on Complex Numbers

1. itsjustme_lol

simplify the expression

2. frx

Ok so start by rewrite $\sqrt{-10}=i \sqrt{10}$

3. itsjustme_lol

ok, im following

4. frx

Do you get that idea?

5. itsjustme_lol

yes I understand that i believe

6. frx

Do the same with sqrt(-5)

7. frx

Then distribute

8. itsjustme_lol

ok so its i$\sqrt{-5}$

9. itsjustme_lol

hang on

10. itsjustme_lol

|dw:1355782789409:dw|

11. frx

Not really, the reason for why you take out the i is that you want the minus under the squareroot to disappear

12. frx

$i \sqrt{5}$

13. frx

Do you know the definition of i?

14. frx

$i=\sqrt{-1}$ $i ^{2}=-1$

15. itsjustme_lol

well i know that i means the y on a plane and it is the imaginary part?

16. frx

That's also, kind of, correct when dealing with imaginary numbers the Y-X plane is called Im-Re

17. frx

So based on the definition of $i=\sqrt{-1}$ what's, for example $\sqrt{-7}$

18. frx

?

19. frx

$i \sqrt{10}(11+i \sqrt{5})$=$11i \sqrt{10}+i ^{2}\sqrt{10}\sqrt{5}= 11i \sqrt{10}-\sqrt{50}$