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e-lub [12.9K]
3 years ago
15

What is the radius of a circle whose equation is x2 + y2 + 8x – 6y + 21 = 0?

Mathematics
1 answer:
s344n2d4d5 [400]3 years ago
3 0

Answer:

2 units

Step-by-step explanation:

The given equation of the circle is:

x^{2} + y^{2}+8x-6y+21=0

The general equation of the circle is:

x^{2} + y^{2}+2gx+2fy+c=0

Comparing the given equation with the general equation we can say:

g = 4

f = -3

c = 21

The formula for radius of the circle is:

radius=\sqrt{g^{2} +f^{2} -c }

Using these values of the given circle, we get:

radius=\sqrt{(4)^{2}+(-3)^{2}-21}\\\\radius=\sqrt{4}\\\\radius=2

Therefore, the length of radius of the given circle is 2.

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Suppose that the regression equation y = 16.99 + 0.32 x1 + 0.41 x2 + 5.31 x3 predicts an adult’s height (y) given the individual
umka21 [38]

Answer:

Step-by-step explanation:

It is given that the regression equation

y = 16.99 + 0.32 x_1 + 0.41 x_2 + 5.31 x_3

predicts an adult’s height (y) given the individual’s mother’s height (x1), his or her father’s height (x2), and whether the individual is male (x3 = 1) or female (x3 = 0).

The coefficient of x1 = 0.32 represents the increase in height of the child due to one inch increase in mother.

Similarly coefficient of x2 = 0.42 represents the increase in height of the child due to one inch increase in father.

and coefficient of x3 = 5.31 represents the increase in height of the child due to being a male than a female.

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3 years ago
Solve this equation using the quadratic formula (preferably): 3x^2 - 4x + 6 = 0
Readme [11.4K]

Answer:

x = 2/3 ± i√14/3

Step-by-step explanation:

5 0
3 years ago
The foot of a ladder is placed 6 feet from a wall if the top of the ladder rests 8 feet up on the wall how long is the ladder?
Vlada [557]
Try to imagine this word problem, there is a wall and a ladder leaning against it, the space from the bottom of the ladder is labeled 6 and the length of the height the ladder reaches on the wall is 8. Imagine this as a right triangle now, where the length of the ladder is the hypotenuse and the length of the legs of the triangle is 6 and 8. Because we know this, we can use the Pythagorean theorem, a^2+b^2=c^2
We then plug in the values and you get 6^2+8^2=c^2
When you simplify, you get 36+64=c^2 which is c^2=100
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4 0
3 years ago
Read 2 more answers
Pls and thanks help me
PIT_PIT [208]
She spent 200 minutes
6 0
2 years ago
What is the equation of the line that passes through the point (3,-3) and has a slope of 0?
Blizzard [7]

Answer:

given us,

slope= 0

(x1y1)= (3,-3)

here

(y-y1) =m(x-x1)

or, (y+3)=0(x-3)

or (y+3)= x-3

or, x+y= -3-3

x+y= -6

Step-by-step explanation:

x+y= -6

7 0
3 years ago
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