Answer:
C: $1500 x 12
Step-by-step explanation:
It's simple. You've gotta multiply to get this answer.
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:
Answer in simplified form is - 10 1/2 .
Step-by-step explanation:
We have given,
(5 1/4) ÷ (- 2 1/2)
This can be simplified as :
(5 1/4) ÷ ( -2 1/2)
Since 5 1/4 = 21/4 and -2 1/ 2 = -5/2
So we can write,
(5 1/4) ÷ ( -2 1/2) = 21/4 ÷ ( - 5/2)
or (21/4) / (-5/2)
or ( 21/4) * (-2/5)
or -42/20
or -21/10
or - 10 1/2 , this is the answer
Hence we get answer in simplified form as -10 1/2
Answer:
hundredths place
Step-by-step explanation:
