SOLUTION: Please sketch this hyperbola and show me how you did it: x^2-y^2=1.

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Question 329720: Please sketch this hyperbola and show me how you did it: x^2-y^2=1.
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Please sketch this hyperbola and show me how you did it: x^2-y^2=1.

The equation

x%5E2%2Fa%5E2-y%5E2%2Fb%5E2=1 is the equation of a hyperbola that opens
right and left with these properties:

1.  The center is at the origin (0,0).

2.  The vertices are the ends of the transverse axis (-a,0) and (a,0).

3.  The endpoints of the conjugate axis are (0,b) and (0,-b).

4.  The foci are the points (-c,0) and (c,0) where c=sqrt%28a%5E2%2Bb%5E2%29

5.  The defining rectangle has the 4 corners 
    (-a,b), (-a,-b), (a,-b), and (a,b)

6.  The asymptotes are the extended diagonals of the defining rectangle
    and have equations y%22%22=%22%22%22%22+%2B-+%28b%2Fa%29x

Your equation is 

x%5E2-y%5E2=1

Write it as 

x%5E2%2F1-y%5E2%2F1=1

and we see that a%5E2=1 and b%5E2=1, so a=1 and b=1,

so:

1.  The center is at the origin (0,0).

2.  The vertices are the ends of the transverse axis (-1,0) and (1,0).

3.  The endpoints of the conjugate axis are (0,1) and (0,-1).

4.  The foci are the points (-c,0) and (c,0) where c=sqrt%28a%5E2%2Bb%5E2%29

    So we calculate c=sqrt%28a%5E2%2Bb%5E2%29=sqrt%281%5E2%2B1%5E2%29=sqrt%281%2B1%29=sqrt%282%29

    and the foci are (-sqrt%282%29,0) and (sqrt%282%29,0) 


5.  The defining rectangle has the 4 corners 
    (-1,1), (-1,-1), (1,-1), and (1,1)

6.  The asymptotes are the extended diagonals of the defining rectangle
    and have equations y%22%22=%22%22%22%22+%2B-+%281%2F1%29x, or
    y%22%22=%22%22%22%22+%2B-+x

So we draw the defining rectangle and its extended diagonals:


    
Now we sketch in the hyperbola:



Edwin