Answer:
D is correct
Step-by-step explanation:
A graph of that sort will make a perfectly mirrored "V" shape, and with no offset, the bottom point will be on the y axis. This means that the first equation will intercept the y axis at zero, the second will intercept the y-axis at -15.
"A" may seem correct also, as the second graph will intercept the x-axis at -15, but it is not complete, as it will intercept that axis at +15 as well.
Answer:
The coordinates of A could be anything in the form of (x, y, z) if you have a third axis. First you count where A is on the x-axis then the y-axis and if you have a 3-dimensional graph then the z-axis.
Step-by-step explanation:
If the co-vertices are (0, 3) and (0, -3) where x is 0 and y has a value, then y is the minor axis. That means that the x axis is the major axis. Because of what the co-vertices are, the center of the ellipse is at the origin. The formula for an ellipse that has a horizontal major axis is
. The a value will always be larger than the b value, therefore, the a value goes under the coordinate that is the major axis. Here, its the x-axis. a is the distance that the outer edge of the ellipse is from the center. It's 8 units away from the center along the x axis and 3 units along the y axis from the center. So a = 8 and a^2 = 64; b = 3 and b^2 = 9. Our formula then is
Assume the parabola is placed on a graph where the x-axis is the top of the dish.
The vertex is then at (0,-30) The x-intercepts or zeros are at (-30,0) and (30,0)
The equation of such parabola would be:
Plug in vertex to find value of 'a'
Now find the focus given that
Answer: the microphone should be placed 7.5 inches from vertex.