## pottersheep 3 years ago Is (+-i√15)/5 equal to +-i√(3/5) ???? Shouldnt i be over 5???

1. TuringTest

$\frac{\sqrt{15}}5=\frac{\sqrt{3\cdot5}}5=\sqrt{\frac35}$

2. pottersheep

Thanks, shouldn'tthe i still be over 5 tho?

3. TuringTest

nope...

4. TuringTest

$\pm i\frac{\sqrt{15}}5=\pm i\frac{\sqrt{3\cdot5}}5=\pm i\sqrt{\frac{3\cdot5}{25}}=\pm i\sqrt{\frac35}$

5. pottersheep

oo but the i was over 5 to begin with

6. TuringTest

but the 5 can move around...

7. pottersheep

ok let me try to process this xD

8. TuringTest

$\pm\frac i5\sqrt{15}=\pm i\frac{\sqrt{15}}5=\pm i\frac{\sqrt{3\cdot5}}5=\pm i\sqrt{\frac{3\cdot5}{25}}=\pm i\sqrt{\frac35}$

9. TuringTest

remember that$\frac{2i}3=i\frac23$not$\frac{2i}3=\frac i3\frac23$

10. TuringTest

$a\frac bc=b\frac ac=\frac{ab}c$

11. pottersheep

:O it is???

12. pottersheep

ooo

13. TuringTest

what else could it be?

14. pottersheep

THANKSSS

15. TuringTest

$\frac{ab}c=a\cdot\frac bc\neq\frac ac\cdot\frac bc$

16. TuringTest

welcome :D