00:01
So in this problem, we're told that a satellite dish is in the shape of a parabolic surface.
00:05
We're told that signals come from a satellite, strike the surface of the dish, and reflect to the focus.
00:10
That's the key point, where the receiver is located.
00:13
Now we're told the satellite dish has a diameter of 16 feet and a depth of 4 feet.
00:17
We want to know how far from the base of the dish should the receiver be placed.
00:20
But notice they tell us that's our focus point.
00:23
So we're trying to find our focus.
00:25
Now the best way to do this is to draw what this parabola would look like.
00:29
And i'm going to draw this specifically so that the vertex is at the origin, 0, 0.
00:35
Now, we're told that the diameter is 16 feet, and if i place the vertex at the origin, that means the distance from my y -axis to both of those endpoints should be the same distance of 8 feet.
00:47
So if i was to label this ordered pair, i know my x -coordinate is 8.
00:52
Well, what would the y -coordinate be? well, we're told that the depth is 4 feet, which would be this distance right here, which means that our y value at this point is equal to 4...