Let X be the number of energy drinks sold.
The manufacturer of an energy drink spends $1.20 to make each drink and sells them for two dollars the manufacturer also has fixed cost each month of $8000.
The manufacturing cost for X energy drinks is

Fixed cost is $8000.
Therefore, cost function is

Selling price of each drink is $2.
Therefore, the revenue function is

Hence, the revenue function is
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:
there is a formula to solve simlar triangle
Step-by-step explanation:
Ratios and properties-similar figures -In depth.if two object have same shape they are called similar.When two figure are similar,The ratios of the length of their corresponding sides are equal.To determine if the triangle shown are similar,Compare their corresponding sides.