conics: find domain, range for xy - 40 = 0, x^2 - y^2 - 4x -

[nigel]

Find domain and range of folowing equations:

1. xy - 40 = 0

2.and x^2-y^2-4x -2y - 1= 0 then after some steps (x-2)^2 - (y-1)^2 = 4

For the first equation, I do not know how to solve for the domain or range. Ffor the second equation, the textbook gave me a different answer for the domain and range.

Please help me find the Domain and Range of these two equation. Thanks Alot! :lol:

Answer for (2): Domain: x < -2 or x > 6; Range: y is any real number

 

[stapel]

The domain is all allowable x-values. What x-values will "work" in the domain for (1)?
The range is all resulting y-values. What do you see when you graph "y = 40/x"?

For (2), put the conic in completed-square form and find the center and vertices to find the domain and range.

If you get stuck, please reply showing (or describing) what you have tried. Thank you.

Eliz.