SOLUTION: 4x^2-3y^2+16x+2y=25/3 Identify if it is a hyperbola, parabola, or ellipse and label the center point, vertex points, focus points, asymptote equations, a length, b length, and c

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: 4x^2-3y^2+16x+2y=25/3 Identify if it is a hyperbola, parabola, or ellipse and label the center point, vertex points, focus points, asymptote equations, a length, b length, and c      Log On


   



Question 927902: 4x^2-3y^2+16x+2y=25/3
Identify if it is a hyperbola, parabola, or ellipse and label the center point, vertex points, focus points, asymptote equations, a length, b length, and c length, and the transverse axis.

Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!



The equation is %28x%5B%22%22%5D%2B2%29%5E2%2F6%22%22%2B%22%22%28y-1%2F3%29%5E2%2F8%22%22=%22%221

The center is %28matrix%281%2C3%2C-2%2C+%22%2C%22%2C+1%2F3%29%29

The vertices are the points %28matrix%281%2C3%2C-2+%2B-+sqrt%286%29%2C+%22%2C%22%2C+1%2F3%29%29 

The foci are the points %28matrix%281%2C3%2C-2+%2B-+2sqrt%282%29%2C+%22%2C%22%2C+1%2F3%29%29

The equations of the asymbtotes in point slope form are

y-1%2F3%22%22+%2B-+expr%282sqrt%283%29%2F3%29%28x%2B2%29

How'd I get all that?

1. I knew it was a hyperbola because the x² and y² terms in

4x%5E2-3y%5E2%2B16x%2B2y=25%2F3 have coefficients of opposite
signs when on the same side of the equation.  But I didn't
know whether it was going to be a hyperbola 
like this: red%28%22%29%28%22%29 or like this: 

So I started with

4x%5E2-3y%5E2%2B16x%2B2y%22%22=%22%2225%2F3
 
Get the  term next to the x² term and the y term next
to the y² term

4x%5E2%2B16x-3y%5E2%2B2y%22%22=%22%2225%2F3

On the left, factor out 4 out of the first two terms 
and -3 out of the last two terms.  The unusual part
is having to factor -3 out of a +2y, for you never had
to do such a thing in basic algebra.  Just remembr that
"to factor out" means "to divide by", so you divide +2y
by -3 and you get expr%28-2%2F3%29y: 

4%28x%5E2%2B4x%29-3%28y%5E2-expr%282%2F3%29y%29%22%22=%22%2225%2F3

Then inside those parentheses you must complete the square:

In the first parentheses:

1. Multiply the coefficient of the x term, which is +4, by 1%2F2,
   getting +2.
2. Square +2 getting +4.
3. Put +4-4 after the x term. (That is, add it and subtract 4, which
   amounts to adding 0)

4%28x%5E2%2B4x%2B4-4%29-3%28y%5E2-expr%282%2F3%29y%29%22%22=%22%2225%2F3 

In the second parentheses:

1. Multiply the coefficient of the y term, which is -2%2F3, by 1%2F2,
   getting -1%2F3.
2. Square -1%2F3 getting %22%22%2Bexpr%281%2F9%29.
3. Put %22%22%2B1%2F9-1%2F9 after the y term. (That is, add it and subtract 1%2F9, which
   amounts to adding 0)

4%28x%5E2%2B4x%2B4-4%29-3%28y%5E2-expr%282%2F3%29y%2B1%2F9-1%2F9%29%22%22=%22%2225%2F3

Group the first three terms in each parentheses:

%22%22=%22%2225%2F3

Factor %28x%5E2%2B4x%2B4%29 as %28x%2B2%29%28x%2B2%29 and then as %28x%2B2%29%5E2

Factor %28y%5E2-expr%282%2F3%29y%2B1%2F9%29 as %28x-1%2F3%29%28x-1%2F3%29 and then as %28x-1%2F3%29%5E2 

and so we have:

4%28%28x%2B2%29%5E2%5E%22%22-4%29-3%28%28y-1%2F3%29%5E2-1%2F9%29%22%22=%22%2225%2F3

Now we have to remove the BIG parentheses by distributing 
without disturbing the smaller parentheses, like this:

4%28x%2B2%29%5E2-16-3%28y-1%2F3%29%5E2+%2B+1%2F3%22%22=%22%2225%2F3

Subtract the 1%2F3 from both sides since that will make a whole
number on the right:

4%28x%2B2%29%5E2-16-3%28y-1%2F3%29%5E2%22%22=%22%2225%2F3-1%2F3

4%28x%2B2%29%5E2-16-3%28y-1%2F3%29%5E2%22%22=%22%2224%2F3

4%28x%2B2%29%5E2-16-3%28y-1%2F3%29%5E2%22%22=%22%228

4%28x%2B2%29%5E2-3%28y-1%2F3%29%5E2%22%22=%22%2224

Now we get 1 on the right by dividing through by 24

4%28x%2B2%29%5E2%2F24-3%28y-1%2F3%29%5E2%2F24%22%22=%22%2224%2F24

%28x%2B2%29%5E2%2F6-%28y-1%2F3%29%5E2%2F8%22%22=%22%221

Now that's in the form of a hyperbola like this red%28%22%29%28%22%29.  

%28x-h%29%5E2%2Fa%5E2-%28y-k%29%5E2%2Fb%5E2%22%22=%22%221

h=-2, k=1%2F3, a=sqrt%286%29, b=sqrt%288%29=2sqrt%282%29

So we have the center.

The foci ar points which are "a" units right and left of the center.

The defining rectangle is 2a units wide and 2b units high.

It's extended diagonals are the asymptotes.

To find the foci we calculate c from c² = a²+b², and they are c
units right and left of the center.

The asymptotes have slopes %22%22+%2B-+b%2Fa and pass through the 
center, so you can find them from the point-slope form.


Edwin