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3 years ago

What are the foci of the graph y2 – 25x2 = 25?

Mathematics

1 answer:

Alborosie3 years ago

7 0

Answer: $\bold{(0,-\sqrt{26})\quad \&\quad (0,\sqrt{26})}$

Step-by-step explanation:

$.\qquad y^2-25x^2=25\\\\\implies \dfrac{y^2}{25}-\dfrac{25x^2}{25}=\dfrac{25}{25}\\\\\\\implies \dfrac{y^2}{25}-\dfrac{x^2}{1}=1\\\\\\Center: (0, 0)\\Length\ of\ foci:25+1=c^2\implies \sqrt{26}=c\\Foci: (0,0\pm \sqrt{26})$

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The ratio of dimes to quarters in a money bag is 2:14. if the total numbers of coins is 48, how many quarters are there?

Bess [88]

Answer:

There are 42 quarters (and 6 dimes).

Step-by-step explanation:

The given ratio is 2:14. But this does not tell us how many dimes nor how many quarters we have. Instead, it's a ratio. Modify this by multiplying numerator and denominator by n and then find n:

Number of dimes 2n

----------------------------- = -----

Number of quarters 14n

Then the total number of coins is 2n + 14n =48, implying that:

16n = 48, or n = 3.

Then the number of dimes is 2(n) = 2(3) = 6, and that of quarters is 14(n) =

14(3) = 42.

There are 42 quarters (and 6 dimes). Notice how the total of 42 and 6 is 48.

7 0

3 years ago

A 4 foot tree was planted in 2012 outside a high school. The tree grew continuously by 22% each year from that point. Find out w

Brut [27]

Answer:

The height of the tree in 2020 was of 19.63 feet.

Step-by-step explanation:

Exponential equation for growth:

The exponential equation for the growth of an amount has the following format:

$H(t) = H(0)(1+r)^t$

In which H(t) is the amount after t years, H(0) is the initial amount and r is the growth rate, as a decimal.

A 4 foot tree was planted in 2012 outside a high school.

This means that $H(0) = 4$

The tree grew continuously by 22% each year from that point.

This means that $r = 0.22$

Find out what the height of the tree was in 2020.

2020 is 2020 - 2012 = 8 years after 2012, so this is H(8).

$H(t) = H(0)(1+r)^t$

$H(t) = 4(1+0.22)^t$

$H(4) = 4(1.22)^t$

$H(4) = 4(1.22)^8 = 19.63$

The height of the tree in 2020 was of 19.63 feet.

6 0

3 years ago

For a criminal trial, 8 active and 4 alternate jurors are selected. Two of the alternate jurors are male and two are female. Dur

aleksley [76]

Answer:

The answer would be 1/6

6 0

3 years ago

A circle has a diameter with endpoints at (6, 5) and (8, 5). Write the equation for the circle.

mario62 [17]

Answer:

$(x-7)^2+(y-5)^2=1$

Step-by-step explanation:

The two things that are required to formulate the equation of the circle is the center coordinate and the radius of the circle!

Center of the circle:

The center of the circle always lies at the midpoint of the endpoints of its diameter: Let's call the endpoints A(6,5) and B(8,5).

Using the midpoint formula we'll get:

$(x_m, y_m) = \left(\dfrac{x_1+x_2}{2},\dfrac{y_1+y_2}{2}\right)$

$(x_m, y_m) = \left(\dfrac{6+8}{2},\dfrac{5+5}{2}\right)$

$(x_m, y_m) = (7,5)$

This is the center coordinate of our circle.

Radius:

The radius of the circle is the distance from the center of the circle to any of the endpoints of the diameter (A or B)

We can use the distance formula:

$r = \sqrt{(x_1-x_2)^2+(y_1-y_2)^2}$

$r = \sqrt{(x_1-x_m)^2+(y_1-y_m)^2}$

$r = \sqrt{(6-7)^2+(5-5)^2}$

$r = \sqrt{1^2}$

$r = 1$

Equation of the circle:

The equation is written as:

$(x-a)^2+(y-b)^2=r^2$

here, (a,b) are the center points of the circle

in our case this is $(a,b)=(x_m,y_m)=(7,5)$

and r = 1

$(x-7)^2+(y-5)^2=1^2$

$(x-7)^2+(y-5)^2=1$

This is the equation of the circle!

3 0

3 years ago

You go to a restaurant and order a $25 worth of food you leave a 20% tip how much total do you leave including tip

s2008m [1.1K]

You leave a total of $30
25 + 25/5 = 25+5=30

6 0

3 years ago

Read 2 more answers