# algebra

posted by
**lee** on
.

A few more question Id like for someone to check please.

1) what are the vertex, focus, and directrix of the parabola with the given equation? x^2-8x-28y-124=0

vertex (4,-5) focus (0,7) directrix y=-12

2) write an equation of a circle with given center and radius. center(-7,-6) and radius 2.

(x+7)^2+(y+6)^2=4

3) write an equation for the translation of x^2+y^2=49 by 3 units left and 4 units up.

(x+3)^2+(y-4)^2=49

4) what is the center and radius of the circle with given equation? (x-1)^2+(y+1)^2=4

center (1,-1) radius 2

5) what is an equation of a parabola with the given vertex and focus? vertex(-2,5) focus (-2,6)

this one don't know

6) a radio station has a broadcast area in the shape of a circle with equation x^2+y^2=5,625 where the constant represents square miles.

graph the equation and state the radius in miles

what is the area of the region in which the braodcast from the station can be picked up.

r=sqrt5623

r=75miles

A=pisqrt2

A=pi(5,625)^2miles

A=17671.49 miles