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Point B has coordinates ​(1​,2​). The​ x-coordinate of point A is negative 8. The distance between point A and point B is 15 units. What are the possible coordinates of point​ A?

2 Answers

4 votes

Final answer:

The possible coordinates of point A are (-8, 14) and (-8, -10).

Step-by-step explanation:

To find the possible coordinates of point A, we need to consider that the x-coordinate of point A is -8 and the distance between point A and point B is 15 units. Since point B has coordinates (1, 2), we can use the distance formula to find the y-coordinate of point A.

The distance formula is given by:
distance = sqrt((x2 - x1)^2 + (y2 - y1)^2)

Substituting the known values,
15 = sqrt((1 - (-8))^2 + (y2 - 2)^2)

Simplifying the equation,
15 = sqrt(81 + (y2 - 2)^2)

Squaring both sides, we get:
225 = 81 + (y2 - 2)^2

Subtracting 81 from both sides, we have:
144 = (y2 - 2)^2

Taking the square root of both sides, we get:
12 = |y2 - 2|

Splitting the equation into two cases,
Case 1: y2 - 2 = 12, which gives y2 = 14
Case 2: -(y2 - 2) = 12, which gives y2 = -10

Therefore, the possible coordinates for point A are (-8, 14) and (-8, -10).

User Jkoestinger
by
5.7k points
2 votes

Answer:

The point A will be (-8,14) or (-8,-10).

Step-by-step explanation:

Point B has coordinates (1,2) and the x-coordinate of point A is - 8.

Let us assume that the coordinates of point A are (-8,k).

Now, given that the point A is 15 units apart from point B.

Therefore, from the distance formula, we can write that


\sqrt{(1 - ( -8))^(2) + (2 - k)^(2)} = 15

Now,squaring both sides, we get


(1 - ( -8))^(2) + (2 - k)^(2) = 225


(2 - k)^(2) = 225 - 9^(2) = 144

⇒ 2 - k = ± 12

k = 14 or -10.

Therefore, the point A will be (-8,14) or (-8,-10). (Answer)

We know that the distance between two points on the coordinate plane (
x_(1), y_(1)) and (
x_(2), y_(2)) is given by


\sqrt{(x_(1) - x_(2))^(2) + (y_(1) - y_(2))^(2)}.

User Domokun
by
5.4k points
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