Posted by Graham on Saturday, January 14, 2012 at 5:34pm.
I have a question concerning this problem:I just want to make sure my formulas are correct before I do problem
It is a hyperbola equation
(y4)^2/49  (x6)^2/72 = 1
1.It is a vertical hyperbola, correct?
2. the a^2 is 49, correct?
3. the b^2 is 72, correct?
4. I find the foci by a^2 + b^2 = c^2, and when I have the square root of "c^2" it would be ( "h" which is 6 in this case, k which is 4 +whatever "c" ended up to be, correct?
5.Vertices for vertical hyperbola is (h,k+a), correct

Algebra IIPlease check fpr explanation  Graham, Saturday, January 14, 2012 at 5:35pm
I forgot one questionin a hyperbola, the "a^2" is always under the first variable, whether it be "x" or "y", correct

Algebra IIPlease check fpr explanation  Reiny, Saturday, January 14, 2012 at 6:37pm
1. correct
2. and 3.
I always associate a^2 with the x's
and b^2 with the y's, but that is a personal choice.
It will depend how your text or your instructor chooses.
regarding your comment, ...
what if I simply changed the equation to
(x6)^2/72  (y4)^2 /49 = 1 , (which is the preferred method of writing it)
would you now label a^2 as 72 ?
Can you see the problem ?
That is why associating a^2 with the x's and b^2 with the y's makes so much more sense.
4. c^2 = a^2 + b^2 = 121
c = 11
foci : (6, 15) and (6, 7)
(your formula for a vertical hyperbola is correct) 
Algebra IIReinyPlease check fpr explanation  Graham, Saturday, January 14, 2012 at 7:10pm
So if I change the formula to = (1), then I have to change the a^2 to be under the "x" is that correct?
Thank you for your help 
Algebra IIPlease check fpr explanation  Reiny, Saturday, January 14, 2012 at 8:40pm
All I did was to multiply each term by 1
I like to have all my conic section equations in standard form, that is ,
my circle, ellipse and hyperbola equations start with the "x" term.
As I said, I associate the a^2 with the x's and the b^2 with the y's.
This saves a lot of confusion.
However, if your instructor wants you to do it otherwise, such as the a's always going with the major axis, then do so. 
Algebra IIPlease check fpr explanation  Graham, Saturday, January 14, 2012 at 9:22pm
okaythank you I got it now