Answer: 1.5 will be on the point of 1 but just a little bit higher. -2 will be plotted exactly on -2
Step-by-step explanation:
$10.99 , divide 54.99 by 5 to get 10.99 for each shirt
Hey!
First, let's find the area. The formula for finding area of a circle is: π · r²
Radius is ½ of the diameter. Divide the diameter by 2 to get the radius.
d = 18
18 ÷ 2 = 9
r = 9
r² = 9 × 9 = 81
The area of the whole pizza is 81π. There are 10 slices. Divide the area of the whole pizza by 10 to find the area of 1 slice.
81π ÷ 10 = 8.1π
<em>That means each slice is 8.1π inches²</em>
<span>Lets find the volume of a cylinder with a diameter D=10 inches and lenght L= 20 inches. First we need to notice that the diameter is twice the size of the radius: D=2r. Then we write the equation for the volume of the cylinder. it is the base times the height: V=pi*r^2 * L. Now we input the nubmers in the equation: V=3.14*(D/2)^2 * L where r=D/2=5 inches and after calculating we get: V=1570 inches^3</span>
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.
