Question:
The distance of the point P(−6, 8) from the origin is
(a) 8
(b) $2 \sqrt{7}$
(c) 6
(d) 10
Solution:
The distance of a point $(x, y)$ from the origin $O(0,0)$ is $\sqrt{x^{2}+y^{2}}$.
Let P(x = −6, y = 8) be the given point. Then
$O P=\sqrt{x^{2}+y^{2}}$
$=\sqrt{(-6)^{2}+8^{2}}$
$=\sqrt{36+64}$
$=\sqrt{100}=10$
Hence, the correct answer is option (d).