Question

I'm stuck! Need help with rationalizing...
Problem: if x = root 6 and y^2 =12, then (4/xy) =

This is what I have so far...
I made y = 2 root 6 so it correspond x= root 6
then I plugged in the x and y. However, I'm stuck at rationalizing it.

(4)/ (2 root 6 * 2 root 6) =
Idk if I'm supposed to do this... (4) / (4 root 6)

I know I have to rationalize it something with root 6, but I don't get the same result in all the multiple choice.. I probably dome something wrong.. So if you can please tell me step by step it would be nice ^ ^

Answer 1

I know I have to rationalize it with root 6, by multiplying both root 6 top and bottom...

Answer 2

Do you mean x = square root of 6??

Answer 3

yup. oops. disregard the y = 2 square root 6.....

Answer 4

lol. scrap everything I said, but I'm still stuck on this problem...

Answer 5

Well try to look at this.
Problem: if x = root 6 and y^2 =12, then (4/xy)
4/xy = 4/[(sqrt6)(sqrt12)
= 4/sqrt(72)
= 4/sqrt (9 * 2^3)
= 4/[2(3sqrt(2))]
= 2/3sqrt(2) -> rationalizing by multiplying num and denum by sqrt(2)
= 2sqrt(2)/6
Therefore, 4/xy = sqrt(2)/3

Answer 6

Thank youuu! I was over thinking this problem too much. whoops.

Answer 7

No problem. Just post again, if you encounter new confusion. :D

Answer 8

Oh, I'm confuse about
= 4/sqrt (9 * 2^3)
= 4/[2(3sqrt(2))]

How and why did this happen?

Answer 9

wait never mind.. lol