OK, so the graph is a parabola, with points x=0,y=0; x=6,y=-9; and x=12,y=0
Because the roots of the equation are 0 and 12, we know the formula is therefore of the form
y = ax(x - 12), for some a
So put in x = 6
-9 = 6a(-6)
9 = 36a
a = 1/4
So the parabola has a curve y = x(x-12) / 4, which can also be written y = 0.25x² - 3x
The gradient of this is dy/dx = 0.5x - 3
The key property of a parabolic dish is that it focuses radio waves travelling parallel to the y axis to a single point. So we should arrive at the same focal point no matter what point we chose to look at. So we can pick any point we like - e.g. the point x = 4, y = -8
Gradient of the parabolic mirror at x = 4 is -1
So the gradient of the normal to the mirror at x = 4 is therefore 1.
Radio waves initially travelling vertically downwards are reflected about the normal - which has a gradient of 1, so they're reflected so that they are travelling horizontally. So they arrive parallel to the y axis, and leave parallel to the x axis.
So the focal point is at y = -8, i.e. 1 metre above the back of the dish.
Answer:
D. liability
Step-by-step explanation:
The Emerson First National Bank is lending you money to buy a new car.
Before an agreement will be reached for any Organization to lend someone money there have to be something like a collateral.
The agreement will in it's document state that there must be a form of a reliability to hold on, such that if something's happen to the car, or you don't meet the paying up time, or something happens to you,they will see something to hold on.
Answer:
8
Step-by-step explanation:
Number x Square x2 Cube x3
2 4 8
Answer:
It would've been more difficult to solve and doing it as shown in EX:2 it's a way easier method to use and remember.
When you add up the sum of the digits, it should be a multiple of three. 21 is 2 plus 1 equals 3, so since 3 is a multiple of three, 21 is divisible by 3
