The center of the circle is (2, - 1) and the radius is 6 units.
The equation for a circle has the generic form x² + y² + 2gx + 2fy + c = 0.
The standard equation of a circle is x² + y² = r².
The polar form of the equation of the circle is (rcosθ)² + (rsinθ)² = p².
Given, The equation of a circle is x² + y² - 4x + 2y - 31 = 0.
We know, In x² + y² + 2gx + 2fy + c = 0, The center of the circle is,
(- g, - f) and radius is .
Therefore, 2gx = - 4x and 2fy = 2y.
2g = - 4 and 2f = 2.
g = - 2 and f = 1.
- g = 2 and - f = - 1.
So, The center is (2, - 1).
And the radius is, .
= .
= .
= 6 units.
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Answer:
centre = (2, - 1), radius = 6
Step-by-step explanation:
Rearrange the equation by placing the x and y terms together and adding 31 to both sides
Given
x² + y² - 4x + 2y - 31 = 0, then
x² - 4x + y² + 2y = 31
Use the method of completing the square
add ( half the coefficient of the x/y term )² to both sides
x² + 2(- 2)x + 4 + y² + 2(1)y + 1 = 31 + 4 + 1
(x - 2)² + (y + 1)² = 36
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r the radius
compare to (x - 2)² + (y + 1)² = 36, then
centre = (2, - 1) and r = = 6
The slope is and the y-intercept is .
This function is written in slope-intercept form, which is . In this form, is the slope and is the y-intercept.
In this case, and , so those are the answers to this problem.
For this case we have that by definition, the equation of a line of the slope-intersection form is given by:
Where:
m: It's the slope
b: It is the cutoff point with the y axis
We have the following equation:
So we have to:
Answer:
3 original price $95 markdown 10%
4 original price $75 markdown 15%
Answer:
1. 150* .40 = 60 so 150 -60 = 90 so the markdown price is $90
2. 18.99*.25 =4.75 (rounded ) so 18.99-4.75 is $14.24 as your markdown price
3. 95 * .10= 9.5 so 95- 9.5 = $85.50 as your markdown price
4. 75*.15=11.25 so 75-11.25=$63.75 as your markdown price
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