Question

Choose the graph that best represents the hyperbola

y^2/81-x^2/25=1

Answer 1

Since it is of the form (y/b)^2 - (x/a)^2 = 1

Therefore it is conjugate hyperbola.
Therefore graph5.gif and graph8.gif are ruled out.

Now vertices of hyperbola are ( 0,+b) and (0,-b)

(y/9)^2 - (x/5)^2 = 1 .

Therefore b = 9

vertices of hyperbola are ( 0,9) and (0,-9)

Therefore graph7.gif is the right answer

Answer 2

you c that if x=0 the y=+9 and -9 => this imlies that graph 7 is the ans...