Question:
Find points on the x-axis, each of which is at a distance of 10 units from the point A(11, −8).
Solution:
Let P (x, 0) be the point on the x-axis. Then as per the question, we have
$A P=10$
$\Rightarrow \sqrt{(x-11)^{2}+(0+8)^{2}}=10$
$\Rightarrow(x-11)^{2}+8^{2}=100$ (Squaring both sides)
$\Rightarrow(x-11)^{2}=100-64=36$
$\Rightarrow x-11=\pm 6$
$\Rightarrow x=11 \pm 6$
$\Rightarrow x=11-6,11+6$
$\Rightarrow x=5,17$
Hence, the points on the x-axis are (5, 0) and (17, 0).