All categories

2 years ago

Find the vertex, focus, directrix, and focal width of the parabola. x2 = 20y

Mathematics

2 answers:

Lana71 [14]2 years ago

5 0

Answer:

Directrix is line with equation y=-5 and focus is the point with coordinates (0,5) with vertex (0,0) and focal width 20 units.

Step-by-step explanation:

Given the equation of parabola i.e

$x^2=20y$

we have to find the vertex, focus, directrix, and focal width of the parabola.

Parabola: $x^2=20y$

$\text{standard equation of parabola}x^2=4by$

Comparing, we get

$4b=20$ ⇒ $b=\frac{20}{4}=5$

Vertex: (0,0)

Focus: (0,b)=(0,5)

Directrix: y=-b ⇒ y=-5

Focal width: 4(5) = 20 units

Directrix is line with equation y=-5 and focus is the point with coordinates (0,5) with vertex (0,0) and focal width 20 units.

sp2606 [1]2 years ago

4 0

The parabola :
x² = 20 y
It is in the standard form : x² = 4 b y
b = 20 : 4 = 5
Vertex : ( 0, 0 );
Focus : <span>( 0,</span> 5 );
Directrix : y + 5 = 0; y = - 5
Focal width: 4 * 5 = 20 units
Answer: A )

You might be interested in

Suppose two different methods are available for eye surgery. The probability that the eye has not recovered in a month is 0.002

umka21 [38]

Answer:

0.4007

Step-by-step explanation:

Let's define the following events:

A: method A is used

B: method B is used

NR: the eye has not recovered in a month

R: the eye is recovered in a month

The probability that the eye has not recovered in a month is 0.002 if method A is used, i.e., P(NR|A) = 0.002, so P(R|A) = 0.998.

When method B is used, the probability that the eye has not recovered in a month is 0.005, i.e., P(NR|B) = 0.005, so P(R|B) = 0.995.

40% of eye surgeries are done with method A, i.e., P(A) = 0.4

60% of eye surgeries are done with method B, i.e., P(B) = 0.6

If an eye is recovered in a month after surgery is done in the hospital, what is the probability that method A was performed? We are looking for P(A|R), then, by Bayes' Formula

P(A|R) = P(R|A)P(A)/(P(R|A)P(A) + P(R|B)P(B)) = 0.998*0.4/(0.998*0.4 + 0.995*0.6) = 0.4007

4 0

2 years ago

Which transformations have been applied to the graph of f(x) = x2 to produce the graph of g(x) = –5x2 + 100x – 450? Select three

RSB [31]

Answer:

The graph of f(x) is shifted up 50 units

The graph of f(x) is shifted right 10 units

The graph of f(x) is reflected over the x-axis

Step-by-step explanation:

we have

$f(x)=x^{2}$

This is a vertical parabola open upward

The vertex is a minimum

The vertex is the origin (0,0)

$g(x)=-5x^{2}+100x-450$

This is a vertical parabola open downward

The vertex is a maximum

The first thing to note is that fx) is a parabola that opens up and g(x) opens down, so a reflection across the x-axis must have been applied.

Find the vertex of g(x)

Convert to vertex form

$g(x)=-5x^{2}+100x-450$

Complete the square

$g(x)=-5(x^{2}-20x)-450$

$g(x)=-5(x^{2}-20x+100)-450+500$

$g(x)=-5(x^{2}-20x+100)+50$

$g(x)=-5(x-10)^{2}+50$

The vertex is the point (10,50)

To translate the vertex of (0,0) to (10,50)

The rule of the translation is

(x,y) ------> (x+10,y+50)

That means ----> The translation is 10 units at right and 50 units up

therefore

The transformations are

The graph of f(x) is shifted up 50 units

The graph of f(x) is shifted right 10 units

The graph of f(x) is reflected over the x-axis

5 0

2 years ago

Read 2 more answers

Simplify the function f (x) = one-third (81) Superscript StartFraction 3 x Over 4 EndFraction. Then determine the key aspects of

Nikitich [7]

Answer:

The answer is given below

Step-by-step explanation:

Given that:

$f(x)=\frac{1}{3}(81)^ \frac{3x}{4} \\Using\ exponent\ rule:a^{xy}=a^xa^y\\f(x)=\frac{1}{3}(81^{1/4})^ {3x}\\f(x)=\frac{1}{3}(3})^ {3x}\\f(x)=\frac{(3)^ {3x}}{3^1} \\Using\ exponent\ rule:a^x/a^y=a^{x-y}\\f(x)=3^ {3x-1}$

The function is an exponential function.

The domain is the set of all independent variables i.e the input values (x values). For an exponential function, the domain is the set of all real numbers. That is:

Domain: x = (-∞, ∞)

The range is the set of all dependent variables i.e the values of y. For an exponential function, the range is the set of all real numbers greater than zero. That is:

Range: y = (0, ∞)

8 0

2 years ago

Read 2 more answers

The indicated function y1(x) is a solution of the associated homogeneous equation. Use the method of reduction of order to find

fenix001 [56]

Answer:

y2 = (6x + 7)/36 + (Dx + E)e^x

Step-by-step explanation:

The method of reduction of order is applicable for second-order differential equations.

For a known solution y1 of a 2nd order differential equation, this method assumes a second solution in the form Uy1 which satisfies the said differential equation. It then assumes a reduced order for U'' (w' = U'').

The differential equation becomes easy to solve, and all that is left are integration and substitutions.

Check attachments for the solution to this problem.

6 0

2 years ago

In a regional spelling bee, the 8 finalists consist of 3 boys and 5 girls. Find the number of sample points in the sample space

posledela

Answer: a.) 40320

b.) 336

Step-by-step explanation:

since we have 8 possible positions, with 8 different candidates, then there are 8 possible ways of arranging the first position, 7 possible ways of arranging the Second position, 6 ways of arranging the 3rd position, 5 possible ways od arranging the 4th position, 4 possible ways of arranging the 5th position, 3 possible ways of arranging the 6th position, 2 possible ways of arranging the 7th position and just one way of arranging the 8th position since we have only one person left.

Hence, the Number of possible sample space for different 8 positions is by multiplying all the number of ways we have in our sample space which becomes:

8*7*6*5*4*3*2*1 = 40320.

b.) By the sample space we have, since we've been asked ti arrange for only the firat 3 positions, then we multiply just for the first 3ways of choosing the positions, this becomes:

8*7*6 = 336

5 0

2 years ago