## bleuspectre one year ago Simplify square root of negative 72. negative 6 square root of 2 6 square root of negative 2 6 square root of 2 i 6 i square root of 2

1. anonymous

$\sqrt{-72} = \sqrt{-1}\sqrt{72} \qquad i=\sqrt{-1}$

2. anonymous

so what are the factors of 72?

3. anonymous

$\sqrt{-72}$ This is the same as i$\sqrt{72}$ 72 is not a perfect square root.|dw:1444365266356:dw| i$\sqrt{3*3*2*2*2}$

4. anonymous

$\sqrt{-1}\sqrt{\color{red}{3 \cdot 3} \color{blue}{\cdot 2\cdot 2\cdot 2}}$

5. anonymous

for every set of 2 of the same numbers, 1 comes out of the square root.

6. anonymous

$\sqrt{3\cdot 3\cdot2\cdot 2\cdot 2} = 3\cdot 2\sqrt{2} = 6\sqrt{2}$

7. anonymous

and $$i=\sqrt{-1}$$

8. bleuspectre

would an I go after the 2?

9. bleuspectre

Like$6\sqrt{2}i$

10. anonymous

yep.

11. bleuspectre

Thank you so much!!!

12. anonymous

np.