ISM 15.1 Circles

What is the standard equation of a circle?

• (x-k)² + (y-h)² = r²

• (x+h)² + (y+k)² = r²

• (x-h)² + (y-k)² = r²

• (k-x)² + (h-y)² = r²

What does (h,k) stand for in the standard circle equation?

• (h,k) is the center of the circle

• (h,k) is a point on the circle.

• (h,k) is a point that we guess and find

• (h,k) is the distance of the circle

What are the coordinates of the center and the radius of the circle with equation:
(x - 4)² + (y - 3)² = 25 ?

• Center (4,3)
  Radius = 5 units
• Center (4,3)
  Radius = 25 units
• Center (-4,-3)
  Radius = 25 units
• Center (-4,-3)
  Radius = 5 units

Write the equation of a circle with center (7, 0) with radius 3.

• (x - 7)² + y² = 9
• x² + (y -7)² = 9
• (x - 7)² + y² = 3
• x² + (y -7)² = 3

What is the equation of the circle that passes through (-15, 10) and has a center at (-16, 11)?

• $\left(x+16\right)^2+\left(y-11\right)^2=4$

• $\left(x+11\right)^2+\left(y-16\right)^2=4$
  

• $\left(x+16\right)^2+\left(y-11\right)^2=2$

• $\left(x+13\right)^2+\left(y-17\right)^2=2$
  

What is the center and radius given the equation, 8x+x²-2y+y²-64=0?

• Center: (-4, 1), Radius: 9

• Center: (4,1), Radius: 9

• Center: (1,-4), Radius: 81

• Center: (-4, 1), Radius: 81

Find the graph to this equation $\left(x-3\right)^2+y^2=4$  

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Find the graph to this equation $\left(x+9\right)^2+\left(y+4\right)^2=48$  

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Find the standard equation of this graph

• $\left(x-1\right)^2+\left(y+4\right)^2=4$

• $\left(x+1\right)^2+\left(y-4\right)^2=16$

• $\left(x-1\right)^2+\left(y+4\right)^2=16$

• $\left(x+1\right)^2+\left(y-4\right)^2=4$

Find the standard equation of this graph

• $x^2+\left(y-3\right)^2=12.25$

• $x^2+\left(y-3\right)^2=3.5$

• $\left(x\ -3\right)^2+y^2=12.25$

• $x^2+\left(y+3\right)^2=3.5$