Given:
Point B has coordinates (4,1).
The x-coordinate of point A is -4.
The distance between point A and point B is 10 units.
To find:
The possible coordinates of point A.
Solution:
Let the y-coordinate of point A be y. Then the two points are A(-4,y) and B(4,1).
Distance formula:
[tex]D=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]
The distance between point A and point B is 10 units.
[tex]\sqrt{(4-(-4))^2+(1-y)^2}=10[/tex]
Taking square on both sides, we get
[tex](8)^2+(1-y)^2=100[/tex]
[tex](1-y)^2=100-64[/tex]
[tex](1-y)^2=36[/tex]
Taking square root on both sides, we get
[tex](1-y)=\pm \sqrt{36}[/tex]
[tex]-y=\pm 6-1[/tex]
[tex]y=1\mp 6[/tex]
[tex]y=1-6[/tex] and [tex]y=1+6[/tex]
[tex]y=-5[/tex] and [tex]y=7[/tex]
Therefore, the possible coordinates of point A are either (-4,-5) or (-4,7).
