PLEASE ANSWER ASAP

The cross section of a parabolic reflector has a vertical axis of symmetry with its vertex at (0,0) . The focus of the reflector

Paha777 [63]

Answer:

The depth of the reflector is 0.84 feet

Step-by-step explanation:

<em>(See the figure below)</em>

The equation of a parabola centered at the origin with an axis of symmetry on y-axis is:

$x^{2}=4py$ (1)

With p the distance from the origin to the focus using p=6, the equation (1) of the parabola becomes:

$x^{2}=4(6)y=24y$ (2)

Note that the point B is on the parabola, so this point should satisfy the parabola equation (2) that allow us to use the value x=4.5 to find the y value associated to it, that it is the depth (h) of the reflector:

$(4.5)^{2}=24y$ , solving for y

$y=\frac{(4.5)^{2}}{24}\approx0.84\,ft$

4 0

4 years ago

A construction zone on Interstate 15 has a speed limit of 40 mph. The speeds of vehicles passing through this construction zone

monitta

Answer:

a. The percentage of vehicles who pass through this construction zone who are exceeding the posted speed limit =90.82%

b. Percentage of vehicles travel through this construction zone with speeds between 50 mph and 55 mph= 2.28%

Step-by-step explanation:

We have to find

a) P(X>40)= 1- P(x=40)

Using the z statistic

Here

x= 40 mph

u= 44mph

σ= 3 mph

z=(40-44)/3=-1.33

From the z-table -1.67 = 0.9082

a) P(X>40)=

Probability exceeding the speed limit = 0.9082 = 90.82%

b) P(50<X<55)

Now

z1 = (50-44)/3 = 2

z2 = (55-44)/3= 3.67

Area for z>3.59 is almost equal to 1

From the z- table we get

P(55 < X < 60) = P((50-44)/3 < z < (55-44)/3)

= P(2 < z < 3.67)

= P(z<3.67) - P(z<2)

= 1 - 0.9772

= 0.0228

or 2.28%

3 0

3 years ago

F(x)=x^3+10x^2+31x+30

Colt1911 [192]

The factors of the given polynomial will be ( x + 2 ), ( x + 5 ) and ( x + 3 ).

<h3>What is an expression?</h3>

Expression in maths is defined as the collection of the numbers variables and functions by using signs like addition, subtraction, multiplication and division.

The given expression will be solved as:-

f(x) = x³ + 10x² + 31x + 30

f(x) = ( x³ + 7x² + 10x + 3x² + 21x + 30

f(x) = ( x² + 7x + 10 ) ( (x + 3 )

f(x) = ( x²+ 5x + 2x + 10 ) ( x + 3 )

f(x) =[ x ( x+ 5 ) +2 ( x+ 5) ] ( x + 3 )

f(x) = ( x + 5 ) ( x + 2 ) ( x + 3 )

Therefore factors of the given polynomial will be ( x + 2 ), ( x + 5 ) and ( x + 3 ).

To know more about Expression follow

brainly.com/question/723406

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5 0