Respuesta :
Answer:
A circle is centered at the point
(−2,5) and has a radius of 7 units.
Which points on the circle have an x-coordinate of 0? (Your answer should be a list of points, such as "(1,1), (2,4)".)
Which points on the circle have a y-coordinate of 2? (Your answer should be a list of points, such as "(1,1), (2,4)".)
Write an equation for the graph of this circle.
Answer:
- See below
Step-by-step explanation:
Given:
- The radius is 7 and
- Center is at (- 2, 5).
The equation is:
- (x - h)² + (y - k)² = r² or
- (x + 2)² + (y - 5)² = 7² or
- (x + 2)² + (y - 5)² = 49
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The points with x = 0:
- (0 + 2)² + (y - 5)² = 49
- (y - 5)² = 49 - 4
- (y - 5)² = 45
- y - 5 = ± √45
- y = 5 ± √45
- y = 5 ± 3√5
The points are:
- (0, 5 + 3√5), (0, 5 - 3√5)
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The points with y = 2:
- (x + 2)² + (2 - 5)² = 7²
- (x + 2)² = 49 - 9
- (x + 2)² = 40
- x + 2 = √40
- x = - 2 ± 2√10
The points are:
- (- 2 + 2√10, 2), (- 2 - 2√10, 2)