Question

can someone help me please?:)

Answer 1

1 step is okay yes
we can square root both sides no problem right?

Answer 2

sure

Answer 3

oh that's second step not first

Answer 4

first is just equation itself

Answer 5

yea

Answer 6

so 1 and 2 no problem

Answer 7

Do you think there is a fault in the 3rd step?

Answer 8

3 now what do you think

Answer 9

look at one side of the equation at a time

Answer 10

sorry, my laptop is lagging,and it step 3 looks fine to me:S

Answer 11

hehe can we do this \(\sqrt{a^2+b^2}=a+b?\)

Answer 12

i guess not lol

Answer 13

Well as @xapproachesinfinity said the R.H.S is fine as \[\sqrt{c^2} = c \] as they cancel

Answer 14

yes it is not allowed

Answer 15

rhs?

Answer 16

But it should be something like \[\sqrt{(a+b)^2}\] to become a+b

Answer 17

right hand side :)

Answer 18

So to get that we know that we want something like \[\sqrt{a^2+2ab+b^2}\]

Answer 19

for this \(\sqrt{b^2+a^2}\) we cannot do anything to it

Answer 20

We cannot? :o

Answer 21

yes we can't as far as the problem is concerned!

Answer 22

We can solve it by adding root(2ab) on both sides?

Answer 23

im confused lol

Answer 24

hmm you meant \(|c|+\sqrt{2ab}=\sqrt{a^2+b^2}+\sqrt{2ab }\)

Answer 25

is that what you saying ?

Answer 26

No that won't do but we can add something to it so it becomes root(a^2+b^2+2ab)

Answer 27

you can't you add 2ab under the root so you must subtract it under the root

Answer 28

Well we shouldn't had done this step in the first place lol :p

Answer 29

this problem we need to go back to a^2+b^2=c^2
solve a
a^2=c^2-b^2
take root
root(a^2)=root(c^2-b^2)
|a|=root(c^2-b^2)
a=+-root(c^2-b^2) the correct approach

Answer 30

We could have done something like

a^2 = c^2 - b^2

so we'd get

a= root(c^2-b^2) for an answer

Answer 31

Lol we just wrote the samething

Answer 32

yeah true

Answer 33

but we need +- too

Answer 34

:S

Answer 35

Agreed

Answer 36

But the ques says +

Answer 37

eh i didn;t read that positive reals part lol

Answer 38

so it has to be a=root(c^2-b^2)

Answer 39

yall are arguing a question which you both know but are not helping the actual person who needs help, both of u just completly confused me

Answer 40

@Sammii09 LoL

Answer 41

ok now we need to promptly do this problem
first step checked
second step no we need to solve for a^2
third step square rroot both sides
4th step a=... that is it

Answer 42

I'm just gonna leave @xapproachesinfinity is here

Answer 43

haha lol @Sammii09

Answer 44

look at my comment before this
i did the problem

Answer 45

ok

Answer 46

first step is okay
2 step no ( we need to isolate a^2 in one side)
3 step (no that's not allowed) (suggest take square root of both side of this equation
a^2=c^2-b^2)
4 step no (since third is wrong 4 will also be wrong) (suggested a=root(c^2-b^2))
done!

Answer 47

okay thanks

Answer 48

no problem