Does it matter where we put i?

[JR Sauerland]

In this problem, they solve for i, and at first, it looks like it will be i*2* square root of 3... Then he puts 2 sqrt of 3 times i. Can it also be 2i sqrt of 3?

 

[Borg]

In this problem, they solve for i, and at first, it looks like it will be i*2* square root of 3... Then he puts 2 sqrt of 3 times i. Can it also be 2i sqrt of 3?

It doesn't matter where you put it as long as it's clear whether i is inside the square root or not. Also, it looks like 13 and not 3.

@Khang Click on the Physics Forums logo or the FORUMS tab. You will see a list of different forums. Select a forum and you will see a Post New Thread button on the top right of the page. Be sure to check the the Terms and Rules in the INFO tab before posting.

 

[JR Sauerland]

It doesn't matter where you put it as long as it's clear whether i is inside the square root or not. Also, it looks like 13 and not 3.

@Khang Click on the Physics Forums logo or the FORUMS tab. You will see a list of different forums. Select a forum and you will see a Post New Thread button on the top right of the page. Be sure to check the the Terms and Rules in the INFO tab before posting.
View attachment 86688

Oops. I'm still a little sleepy. I'm saying that because someone told me I was wrong. I was seriously confused because I've seen professors write it as 2i sqrt of 13...

 

[jasonRF]

In this problem, they solve for i, and at first, it looks like it will be i*2* square root of 3... Then he puts 2 sqrt of 3 times i. Can it also be 2i sqrt of 3?

JR Souerland,
The order does not matter. Complex number satisfy the commutative property $z_1 z_2 = z_2 z_1$, for any two complex numbers $z_1$ and $z_2$. They also have the associative property $z_1 (z_2 z_3) = (z_1 z_2) z_3$.

jason

 

[NascentOxygen]

In this problem, they solve for i, and at first, it looks like it will be i*2* square root of 3... Then he puts 2 sqrt of 3 times i. Can it also be 2i sqrt of 3?

Yes. But it's better to position the imaginary number i [/size] where it will not be easily overlooked, so in an expression write it first or else last, but don't hide it somewhere in the middle.

 

[Borg]

Oops. I'm still a little sleepy. I'm saying that because someone told me I was wrong. I was seriously confused because I've seen professors write it as 2i sqrt of 13...
View attachment 86689

Well from your image, it looks like it says 2i divided by sqrt 13. That would be wrong.

 

[NascentOxygen]

Oops. I'm still a little sleepy. I'm saying that because someone told me I was wrong.

In that image, you show an expression that includes a division sign. That's presumably why you were told it would not be equivalent?

 

[JR Sauerland]

In that image, you show an expression that includes a division sign. That's presumably why you were told it would not be equivalent?

Yeah, I realized that after. I had gotten used to square root being expressed as /sqrt due to Mathway -_- and mylabsplus also uses /sqrt to create a square root sign lol. Woe is me.