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Mathematics 13 Online
mathslover (mathslover):

Again confusion..

mathslover (mathslover):

\[\large{x^2=1, \textbf{then x = ? }}\] \[large{x=\sqrt{1}, \textbf{then x = ?}}\]

mathslover (mathslover):

*\[\large{x=\sqrt{1}, \textbf{then x = ?}}\]

mathslover (mathslover):

in the first case we have : \(x= \pm 1\)

mathslover (mathslover):

but in the second case we have : x = 1... Correct?

hartnn (hartnn):

no confusion. x^2=1 is quadratic, it must have 2 roots, 1 and -1 x=root1 is linear, it must have only one root = 1

mathslover (mathslover):

Ok so, now let us take the second equation : \[\large{x=\sqrt{1}}\] \[\large{x^2=(\sqrt{1})^2}\] \[\large{x^2=1}\]

mathslover (mathslover):

correct?

hartnn (hartnn):

when you are squaring, u are attaching one more root to x, (x=-1)

OpenStudy (aravindg):

@mathslover i am praying to 3 gods for you :P

OpenStudy (aravindg):

yep what @hartnn said is right

OpenStudy (aravindg):

thats the fallacy here

mathslover (mathslover):

I didn't get you exactly @hartnn ?

OpenStudy (aravindg):

@mathslover when you squared in 2nd step you also attach (-1)^2 = x^2

OpenStudy (unklerhaukus):

\[x^2=1\]\[x=\pm\sqrt 1\]

mathslover (mathslover):

Oh yes right @UnkleRhaukus @AravindG sorry again .... any example?

OpenStudy (shaik0124):

@unkle is right

mathslover (mathslover):

Why did you include pm there @UnkleRhaukus ?

OpenStudy (dape):

It's just a matter of notation, √1 refers to the principal square root of 1, which is 1. But in actuality there are two solutions to the equation x=√1, -1 and 1.

mathslover (mathslover):

Confused..

OpenStudy (aravindg):

@dape x=\[\sqrt 1\] has only one solution =1

OpenStudy (aravindg):

x^2=1 has two solutions which are -1 and +1

OpenStudy (aravindg):

@mathslover just use the theory of equations

OpenStudy (shaik0124):

i agree with arvind

OpenStudy (unklerhaukus):

\[x^2=1\] \[x_{1,2}=\sqrt 1, -\sqrt1\]\[\qquad=\pm\sqrt 1\]

OpenStudy (aravindg):

as you can see a x^2 polynomial will have two roots

hartnn (hartnn):

let x=a now when your are squaring, u do x*x=a*a--->x^2=a^2 but here u also attach here x=-a so x*x=(-a)*(-a) which also is the solution of x^2=a^2

OpenStudy (amistre64):

x^2 only has an inverse if we restrict the domain

OpenStudy (dape):

It's just notation, in actuality the nth root of a number x is \(defined\) to be a number y, which when raised to the nth power is x, or \[ y^n=x \] According to this definition, which is the only one i've ever seen. Both -1 and 1 is a 2nd root (square root) of 1. We usually just take the symbol √ to mean the principal square root (the positive root).

OpenStudy (amistre64):

if we ignore it as a "fucntion" then sqrt(x) is|dw:1348233662431:dw|

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