How can I solve the problem using substitution, and how can it be solve using elimination

Find an equation of the circle that satisfies the given conditions. (Give your answer in terms of x and y.) Center at the origin

Elanso [62]

Answer:

The equation of circle is $x^2+y^2=65$ .

Step-by-step explanation:

It is given that the circle passes through the point (8,1) and center at the origin.

The distance between any point and the circle and center is called radius. it means radius of the given circle is the distance between (0,0) and (8,1).

Distance formula:

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

Using distance formula the radius of circle is

$r=\sqrt{\left(8-0\right)^2+\left(1-0\right)^2}=\sqrt{65}$

The standard form of a circle is

$(x-h)^2+(y-k)^2=r^2$ .... (1)

where, (h,k) is center and r is radius.

The center of the circle is (0,0). So h=0 and k=0.

Substitute h=0, k=0 and $r=\sqrt{65}$ in equation (1).

$(x-0)^2+(y-0)^2=(\sqrt{65})^2$

$x^2+y^2=65$

Therefore the equation of circle is $x^2+y^2=65$ .

5 0

3 years ago

17. Which of the following is the correct formula for finding power in a DC circuit? A. P = I2R B. P = VR C. P = IR D. P = V2I

netineya [11]

Answer:

Choice A. P = I² · R where

P is the power in the DC circuit,
I is the current through the circuit, and
R is the total resistance of the circuit.

Step-by-step explanation:

Electrical power is the rate at which the electrical force does work. So what is electrical work? That's the work $W$ that the electrical force do when it moves charges $Q$ across a potential difference $V$ :

W = $V\cdot Q$ .

The power is the rate at which the electrical force do the work:

$\displaystyle P = \frac{W}{t} = V \cdot \frac{Q}{t}$ .

On the other hand, current $I$ is the charge through a cross-section of the circuit in unit time. By the definition of current:

$\displaystyle\frac{Q}{t} = I$ .

$\displaystyle P =V \cdot \frac{Q}{t} = V\cdot I$ .

Consider Ohm's Law:

$V = I \cdot R$ .

Therefore

$\displaystyle P = V\cdot I = (I \cdot R) \cdot I = I^{2}\cdot R$ .

6 0

4 years ago

Read 2 more answers

What value of x will make the question below truw?

MatroZZZ [7]

1/2 (6x - 10) + 10 = 5x - 13

(6x/2) - (10/2) + 10 = 5x - 13

3x - 5 + 10 = 5x - 13

3x - 5x = -13 + 5 - 10

-2x = -18

x = -18 / -2

x = 9

D.) x = 9

7 0

3 years ago

The chart below shows the average number of movies seen per person in selected countries. Use equal intervals to make a frequenc

NARA [144]

To make a frequency table, you will need to find the lowest and highest average number of movies.

Numbers go from 0.5 to 4.5.
And example of frequencies you could use are:

0-0.9 (1)
1-1.9(5)
2-2.9(5)
3-3.9(2)
4-4.9(1)

The frequencies are in parentheses beside the intervals.

6 0

3 years ago

A jeweler wants to minimize business costs and has found that the average cost in dollars per necklace is given by C(x)=0.5x^2-7

Vika [28.1K]

Answer:

The maximum cost is 41 dollars per necklace.

Step-by-step explanation:

The average cost in dollars/necklace is given by :

$C(x)=0.5x^2-7x+65.5$ .....(1)