solution is first os all find median
median is( 45+61)/2=53
find median of no in left of 53
it is 37
find median of no in right of 53
it is 64
now interquartile range=64-53=27
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.
9514 1404 393
Answer:
1. proportional, 6
2. not proportional
Step-by-step explanation:
<u>Table 1</u>
Each y-value is 6 times the corresponding x-value, so the variables are proportional, and y = 6 times x.
<u>Table 2</u>
The ratios of y to x are 2, 4, 8, so are not the same. The values are not proportional.
Answer:
triangle LMN is similar to triangle RST
Step-by-step explanation:
15/3 - 14/2
This is the expression you are looking for
( I'm not 100% sure but I believe this is correct ! )
