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I need some help with math

#1 rewrite this in standard form, then state the center of the circle as an ordered pair and identify the radius. Show your work
y^(2)-14y+x^(2)-4x+37=0

#2 Write the equation of the circle with center (-2,15) and radius 3.

1 Answer

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Answer:


(y-7)^2+(x-2)^2=16

and


(x+2)^2+(y-15)^2 = 9

Explanation:

The standard equation of a circle is
(x-h)^2+(y-k)^2=r^2 where the coordinate (h,k) is the center of the circle.

Second Problem:

  1. We can start with the second problem which uses this info very easily.
  2. (h,k) in this problem is (-2,15) simply plug these into the equation.
    (x--2)^2+(y-15)^2=r^2 .
  3. We can also add the radius 3 and square it so it becomes 9. The equation.
  4. This simplifies to
    (x+2)^2+(y-15)^2 = 9.

First Problem:

  1. The first problem takes a different approach it is not in standard form. But we can convert it to standard form by completing the square.

  2. y^2-14y+x^2-4x+37=0 first subtract 37 from both sides so the equation is now
    y^2-14y+x^2-4x=-37.

  3. y^2-14y+x^2-4x+37=0 by adding
    (-(b)/(2a) )^2 to both the x and y portions of this equation you can complete the squares.
    (-(b)/(2a))^2=(-(-14)/(2(1)))^2 and
    (-(-4)/(2(1)))^2 which equals 49 and 4.
  4. Add 49 and 4 to both sides and the equation is now:
    y^2-14y+49+x^2-4x+4=-37+49+4 You can simplify the y and x portions of the equations into the perfect squares or factored form
    (y-7)^2 and
    (x-2)^2.
  5. Finally put the whole thing together.
    (y-7)^2+(x-2)^2=16.

I hope this helps!

User Gilean
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