trig
posted by
lindsey
.
The cross section of a television antenna dish is a parabola. A dish has a receiver that is located at the focus, 4 ft. above the vertex.
Find the equation. (which I did)  x^2 = 8y
If the dish is 8 feet wide, how deep is it?

trig 
Damon
so x = +/ 4 if 8 wide
what is y ?
16 = 8 y
y = 2

trig 
lindsey
Wow. Do I just substitute x with 8, and then solve to get y=5?

trig 
Lindsey
Oops nevermind, sorry.

trig 
Damon
No, x is half the width.