Question

Help. I'm learning about radical equations and I;m confused about how √U = -8 is undefined. Can someone explain to me why please.

Answer 1

@Nnesha

Answer 2

hello

Answer 3

ello o^_^o

Answer 4

os is it \[\huge\rm \sqrt{U}= \sqrt{-8} \] ?

Answer 5

wait what?

Answer 6

sqrt u = sqrt -8 ?

Answer 7

I don't think so

Answer 8

I thought you square both sides to get rid of the square symbol

Answer 9

and it gets me \[U = 64\]

Answer 10

no i'm asking a question
so question is \[\sqrt{u}= -8\]

Answer 11

root symbol*

Answer 12

yes

Answer 13

okay yes take square both side to get rid of square root

Answer 14

and it got me \[U = 8\] but the book says it has no solution

Answer 15

whoops

Answer 16

\[U=64\]

Answer 17

yes right take square both side \[(\sqrt{u})^2 = (-8)^2\]

Answer 18

yep right now 64 is an extraneous solution
meaning when you plug it back you wouldn't get equal sides

Answer 19

replace u by 64 in the original equation

Answer 20

Oh I think I get it now

Answer 21

yep \[\huge\rm \sqrt{64}= -8 \] ?
solve it
both sides are equal ?

Answer 22

Nope

Answer 23

\[8 = -8\]

Answer 24

Ok, so thats why it says its no solution than

Answer 25

so yes both sides are not equal that's why no solution
64 is an extraneous solution

Answer 26

Thank you so much! That really helped me out.

Answer 27

my pleasure :-)