Ask question

Ask question

All categories

3 years ago

6

Find the standard form of the equation of the parabola with a focus at (-2, 0) and a directrix at x = 2.

1 answer:

7nadin3 [17]3 years ago

3 0

Answer:

$y^2=-8x$

Step-by-step explanation:

The directrix intersects the x-axis at point (2,0). Points (-2,0) and (2,0) are symmetric about the origin, so the vertex of the parabola is placed at the origin (0,0).

The parameter p of the parabola is the distance from the focus to the directrix, thus p=4.

The branches of the parabola go in negative direction of x-axis, because the focus lies to the left from the vertex.

The equation of the parabola is

$(y-0)^2=-2\cdot 4\cdot (x-0),\\ \\y^2=-8x.$

You might be interested in

Will mark brainliest!!!!!!! Please help!! 18 points for right answer!

Sonbull [250]

I think it should be 1.7?

a^2 + b^2 = c^2

c^2 = 16

Square root of 16 is 4.

1 + 3 = 4

Square root of 1 is 1 and square root of 3 is given, which is 1.7.

An equilateral has two right triangles out together, so basically that would be a rectangle.

1 x 1.7 = 1.7

4 0

3 years ago

Read 2 more answers

85% of the students in Yvan’s school walk to school. If 816 students walk to school, how many students are in the school?

storchak [24]

<h2>Hello There today we will solve your problem</h2>

$\huge\red{\mid{\underline{\overline{\textbf{QUESTION}}}\mid}}$

<em>85% of the students in Yvan’s school walk to school. If 816 students walk to school, how many students are in the school?</em>

<em />

<em>Response-</em>

Since we are using percents we can make an equation out of this question

$\frac{85}{100}=\frac{816}{x}$

$\frac{85}{100}$ is the way we write percents in math as a fraction

and $\frac{816}{x}$ is the part and whole you gave us

$\frac{85}{100}=\frac{816}{x}$ cross multiply

$85x=81600\\divide\\x=960$ students are in the school

$\huge\blue{\mid{\fbox{\tt{ANSWER}}\mid}}$

$960$ students at Y'vans school

6 0

3 years ago

What is the length of a rectangle with width 14in. and area 91in.²?

sleet_krkn [62]

Answer:

91 divided by 14 = 6.5 is the length

Step-by-step explanation:

Whenever given an area and 1 given length always divide the area by the length to find the missing length.

7 0

3 years ago

How long will it take Birr 500

notka56 [123]

It would take 25 years for Birr 500 to quadruple if invested at a rate of 12% simple interest per annum.

<h3 /><h3>Simple interest formula</h3>

Using the simple interest formula A = P(1 + rt) where

P = princial amount = Birr 500,
A = final amount = 4P (since it is quadrupled),
r = rate = 12% = 12/100 = 0.12 and
t = time to quadruple

<h3 /><h3>Finding the time it takes to quadruple </h3>

Since we require t, making t subject of the formula, we have

t = [(A/P) - 1]/r

Substituting the values of the variables into the equation, we have

t = [(A/P) - 1]/r

t = [(4P/P) - 1]/0.12

t = [4 - 1]/0.12

t = 3/0.12

t = 25 years

So, it would take 25 years for Birr 500 to quadruple if invested at a rate of 12% simple interest per annum.

Learn more about simple interest here:

brainly.com/question/25793394

4 0

3 years ago

Sonya is 13 4 5 years old. Bill is 1 1 6 years older than Sonya and Jane is 1 1 3 years older than Bill. How old is Jane?

attashe74 [19]

Answer: 1574

Step-by-step explanation:

1345 plus 116 equals 1461

1461 plus 113 equals 1574

7 0

3 years ago