How do you find the coordinates of the vertices, foci, and the equation of the asymptotes for the hyperbola (x+1)^2/4-(y+3)^2/9=1?

1 Answer
Mar 25, 2018

The vertices are (-3,-3) and (1,-3) , focii are
((-1-sqrt13),-3) and ((-1+sqrt13),-3) asymptotes
are
y=3/2x-3/2 and y= -3/2x-9/2

Explanation:

(x+1)^2/4- (y+3)^2/9=1; h=-1,k=-3,a=2 , b= 3

This is standard form of the equation of a hyperbola with center

(h,k) ; (x-h)^2/a^2-(y-k)^2/b^2=1 :. Centre (-1,-3)

The vertices are a units from the center, and the foci are

c units from the center. Moreover c^2=a^2+b^2

c ((-1-2),-3) and ((-1+2,3) or

(-3,-3) and (1,-3) ; c^2= 2^2+3^2=13

:. c= +- sqrt13 :. Focii are at

((-1-sqrt13),-3) and ((-1+sqrt13),-3)

Each hyperbola has two asymptotes that intersect at the center of

the hyperbola. The asymptotes pass through the vertices of a

rectangle of dimensions 2a=4 and 2b=6 with its

centre at (-1,-3) :. slope +-b/a=+- 3/2 Equation of

asymptotes are y+3= +-3/2(x+1) or y=-3+-3/2(x+1)

or y=3/2x-3/2 and y= -3/2x-9/2 [Ans]