Question

PLEASE HELP!!
Simplify using i. √-15 √-4

Answer 1

\[\sqrt{-1}=i\]
you have this:
\[\sqrt{-1} \sqrt{-1} \sqrt{15}\sqrt{4}\]

Answer 2

replace the sqrt(-1)s with i

Answer 3

and you can do sqrt(4) I'm sure.

Answer 4

so would it be i sqrt 15 and i sqrt 4?

Answer 5

@myininaya

Answer 6

well i*i is not i

Answer 7

do you know what i^2 equals?

Answer 8

\(\bf \sqrt{-15}\cdot \sqrt{-4}\implies \sqrt{-1\cdot 15}\cdot \sqrt{-1\cdot 4}\implies \sqrt{-1}\cdot \sqrt{15}\cdot \sqrt{-1}\cdot \sqrt{4}
\\ \quad \\
\sqrt{-1}\cdot\sqrt{-1}\cdot \sqrt{15}\cdot \sqrt{4}\implies i\cdot i\cdot \sqrt{15\cdot 4}\)

Answer 9

sqrt -2 right?

Answer 10

nope

Answer 11

\(\bf i^2\implies \sqrt{-1}\cdot\sqrt{-1}\implies \sqrt{(-1)^2}\implies ?\)

Answer 12

this should be something your teacher told you
I'm sure
think back to the lecture
your teacher most likely said what i^2 is equal to

Answer 13

ohh -1

Answer 14

ok
and what is sqrt(4)

Answer 15

\[i*i \sqrt{4} \sqrt{15}=-1 \sqrt{4} \sqrt{15} \]

Answer 16

what integer numbers times itself will give you 4?

Answer 17

2

Answer 18

so sqrt(4)=2
so you have
\[-1(2) \sqrt{15}=-2 \sqrt{15}\]

Answer 19

i wrote -2 (in front of sqrt(15) instead of -1(2) since -1 times 2 is -2

Answer 20

Ohh okay, I think I get it now, Thanks @myininaya

Answer 21

np
do you want to try one on your own and I check it?

Answer 22

\[\sqrt{-9} \sqrt{-16}\]