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MathEd-PII

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volunteer
And for your first expression, you got square root of X minus 1 equals 0, so you got a square root of X equals 1 square both sides, you just get X is equal to 1.
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volunteer
Right, just a single root out of that.
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volunteer
Then you go to your 2nd 1.
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volunteer
Which is 9 root X + 1 equals 0.
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volunteer
Then you subtract.
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volunteer
Equals -1.
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volunteer
Um, but I'm a rewrite -1.
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volunteer
To equal
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volunteer
I squared.
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volunteer
So then if I square both sides,
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volunteer
Take the whole thing.
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volunteer
And squared, then I get 81.
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volunteer
X is equal to 14th.
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volunteer
So then X is equal to 14/81, which Ida the 4th is still just one.
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volunteer
But it helps the algebra later.
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volunteer
So you know your X is equal to 1 is is works as a route. So we plug in.
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volunteer
To G of X, we plug in GO
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volunteer
I to the 4th over 81.
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volunteer
Yes, to equal to 9.
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volunteer
I to the 4th over 81.
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volunteer
-8.
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volunteer
Square root and the 4th.
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volunteer
For anyone
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volunteer
-1
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student
you chose only x=1 becuz when we put x = -1, it doesn't statisfy the equation righht?
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volunteer
Uh, then you evaluate, you get 1/9 out of the 4th.
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volunteer
Where did you get X is equal to -1?
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volunteer
So
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volunteer
X can't and in this instance, X can't be equal to -1 because it came from a square root.
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volunteer
That would mean, that would mean here that X is equal to -1
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volunteer
I squared.
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volunteer
It'll work the same too, but
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volunteer
Actually be Ida the 4th, so it'd still be a
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volunteer
Um,
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student
ohh, got it! I was doing it wrong
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volunteer
Like you only get your plus or minus when you, when you take the square root, but in this answer, we were squaring it.
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volunteer
So X has to be positive.
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volunteer
If we have the square root of X equals 1, X has to be positive, so we can't consider the negative one.
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student
yeah, right.
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student
got it!
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volunteer
Right? So think of, so go back. So if you, if you even try to plug it in as a route, uh, to your
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volunteer
Other expression, just the 9 square of x + 1 into the square root of X minus 1. If you try to plug in a negative 1, you'll have 9 I + 1 times I minus 1.
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volunteer
Right, and that wouldn't
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volunteer
That obviously wouldn't work as a route.
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volunteer
So it wouldn't, it wouldn't even hold.
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volunteer
Anyway, uh, get back to my fancy pants.
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volunteer
So, minus 8/9.
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volunteer
I 2 minus 1, and we, we, um, substitute back in what eyes are.
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volunteer
So we get uh 1/9, because out of the 4th there's just 1, I squad is -1, so you get 19 plus 8/9 minus 1 gives you 0.
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volunteer
At least that's, I think that's how you do it. Normally, a complex number is like A + BI.
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student
yeah
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volunteer
But you can't really do that with the square root.
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volunteer
At least I've never seen a square root of a complex number.
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volunteer
He asked that.
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volunteer
kind of square root.
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volunteer
complex number.
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volunteer
Huh, square root of a complex numbers always returns.
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volunteer
A conjugate pair
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volunteer
Mm.
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volunteer
I understand very little.
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student
how squar root of complex number gives conjugate pair ?
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volunteer
That's what I'm saying.
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volunteer
They even bolded it for me, they highlighted it.
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volunteer
Uh, let's see.
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volunteer
I guess it's
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volunteer
The conjugate pair.
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volunteer
Of the square root of the
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volunteer
Oh, this is normalized. B over B.
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volunteer
Absolute value.
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volunteer
And A is 0.
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volunteer
Then you just get the
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volunteer
Really get
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volunteer
Be over the square root of B over 2.
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volunteer
you really see.
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volunteer
to calculate the magnitude.
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volunteer
Mm
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volunteer
OK, that kind of makes sense, really ugly.
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volunteer
Oh, it's gonna be absolute value.
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volunteer
So that's probably why it came out to um
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volunteer
This square root of X is equal to 1. This X is probably absolute value.
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volunteer
So you're right, it could have been -1.
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volunteer
But we don't see absolute value anywhere else.
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volunteer
B or be absolute value.
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student
no, i wasn't right. sqr of x will be only 1
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volunteer
Oh, oops.
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volunteer
I went to another website and I'm still only showing you.
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volunteer
To close this.
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volunteer
I feel like
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volunteer
-1 would work if that square root was an abs was an absolute value of X.
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volunteer
So if it was the square root of absolute value of X.
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volunteer
Then yeah, that would work. You'd square both sides, and then you would, um,
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volunteer
Take the inverse of the absolute value in consider both sides, plus or minus.
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volunteer
But that would give two roots.
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volunteer
And we have a polynomial of
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volunteer
It's a degree of one, but we have the square roots, so it almost bumps it up.
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volunteer
I guess it guarantees that it's gonna be a um one reel and one unreal, or one complex root.
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volunteer
Let's see what's it.
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volunteer
What's the degree of a pole a meal with.
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volunteer
square roots.
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volunteer
Huh
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