Give the coordinates of the circle's center and its radius.
(x−1)^2 +(y+8)^2 =16
a. (-1,8);r=4
b. (1,-8);r=16
c. (1,-8);r=4
d. (-1,8);r=16
e. none of these
Find the vertex and focus of the parabola.
(y-2)^2 +16(x-3)=0
a. vertex: (3,2) focus: (3,-2)
b. vertex: (-3,-2) focus: (-3,-18)
c. vertex: (-3,-2) focus: (-3, 14)
d. vertex: (3,2) focus: (-1,2)
e. vertex: (-3,-2) focus: (-7,-2)
(x−1)^2 +(y+8)^2 =16
Center= ( 1, -8) Radius = 4 → 'd"
(y-2)^2 +16(x-3)=0 put into this form
(x - h) = (1/[4p] ) (y - k)^2 where (h,k) is the vertex and the focus is given by [h + p , k]
(x - 3) = - (1/16)(y -2)^2
The vertex is (3, 2) this parabola opens to the left, and we can find p thusly :
- [1/16 ] = [1/ (4p) = so p = - 4
So the focus = (3 + (- 4 ) , 2 ) = ( -1, 2)
"d" is the correct choice