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avatar+118667 
+1

Um I thought it was, but I didn't look properly and you did not expressly ask me to look.  Sorry.   laugh

I will give you a more comprehensive answer.

 

 

First, draw a rough sketch, this will be enough to tell you that y must be greater than 2.  It will also tell you that there is only one y value (but 2 x vales for the solution.)

\(y = x^2+2\)      is a concave up parabola. The axis of symmetry is the y axis and the vertex is (0,2)   

                You should have enough knowledge to know this. 

 

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\( y^2 - mx^2 = 1\)   is a hyperbola so long as m is positive real number

 

Hypperbolas of the form  \(​​\frac{x^2}{a^2}-\frac{y^2}{b^2}=1\)      have a vertical axis, the y axis is the axis of symmetry and a ist the y intercept

 

So in our case, a=+/-1    So the vertices are (0,1) and (0,-1)

 

So this is our initial sketch.  The red is the parabola and the blue is the hyperbola.

 

 

 

m will change the steepness of the hyperbola so you want to find the m that will make the graph look like this.

 

 

So by now you should at least understand what you are being asked, as far as the outcome goes.

 

-------------------------------

 

So now you have to solve  

 

\(y=x^2+2\qquad and \qquad y^2-mx^2=1\qquad \text{simultaneously}\\ \text{we know already}\\ \text{ m is positive and y is positive and there is only one value of y}\)

 

\(y=x^2+2\qquad and \qquad y^2-mx^2=1\\ x^2=y-2\qquad and \qquad x^2=\frac{1-y^2}{-m}\\ so\\ y-2=\frac{1-y^2}{-m}\\ -my+2m=1-y^2\\ y^2-my+(2m-1)=0\\\)

now solve using the quadratic formula

 

y will be in terms of m but if you know roughly what it looks like you will know that there is only one solution.

 

So the discriminant must be 0.  

 

From this, the value of m can be determined.

 

You are welcome to ask questions (tell me what you have done though)

 

 

 

 

 

LaTex:

y=x^2+2\qquad and \qquad y^2-mx^2=1\\
x^2=y-2\qquad and \qquad x^2=\frac{1-y^2}{-m}\\
so\\
y-2=\frac{1-y^2}{-m}\\
-my+2m=1-y^2\\
y^2-my+(2m-1)=0\\

Oct 23, 2020
Oct 22, 2020

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