{"id":754,"date":"2023-04-30T10:00:12","date_gmt":"2023-04-30T04:30:12","guid":{"rendered":"https:\/\/www.aplustopper.com\/?p=754"},"modified":"2023-05-01T09:30:12","modified_gmt":"2023-05-01T04:00:12","slug":"distance-between-two-points","status":"publish","type":"post","link":"https:\/\/www.aplustopper.com\/distance-between-two-points\/","title":{"rendered":"Distance Between Two Points"},"content":{"rendered":"

Distance Between Two Points<\/h2>\n

Distance Between Two Points Formula<\/h3>\n

\"Distance<\/p>\n

(1) Distance between two points on X-axis :<\/strong>
\nThe coordinate axes in the coordinate plane can be treated as number lines.
\nIf P(x1<\/sub>, 0) and Q(x2<\/sub>, 0) are two points on X-axis, the distance between them is taken as
\nPQ = |x1<\/sub>-x2<\/sub>| ……….(i)
\n\"Distance
\n(2) Distance between two points on Y-axis:
\nIf the points A(0, y1<\/sub>) and B(0, y2<\/sub>) are two points on Y-axis, the distance between them is taken as
\nAB = |y1<\/sub>-y2<\/sub>| ……….(ii)
\n\"Distance<\/p>\n

(3) Distance between P(x1<\/sub>, y1<\/sub>) and Q(x2<\/sub>, y2<\/sub>):<\/strong>
\nLet P(x1<\/sub>, y1<\/sub>) and Q(x2<\/sub>, y2<\/sub>) be two given points in the coordinate plane.
\nLet M and N be the feet of perpendiculars from P(x1<\/sub>, y1<\/sub>) and Q(x2<\/sub>, y2<\/sub>) respectively to X-axis.
\n\"Distance
\n\u2234 M and N are respectively (x1<\/sub>, 0) and (x2<\/sub>, 0).
\nMN = |x1<\/sub>-x2<\/sub>| ……….(i)
\nLet R and S be the feet of perpendiculars from P(x1<\/sub>, y1<\/sub>) and Q(x2<\/sub>, y2<\/sub>) to Y-axis.
\nR and S are respectively (0, y1<\/sub>) and (0, y2<\/sub>).
\nRS = |y1<\/sub>-y2<\/sub>| ……….(ii)
\nLet PR and QN intersect in T.
\nClearly in \u2206PQT, \u2220PTQ is a right angle.
\nUsing Pythagoras’ theorem we have,
\nPQ2<\/sup> = PT2<\/sup> + QT2<\/sup> = MN2<\/sup> + RS2<\/sup>
\nbecause QTRS and PTNM are rectangles.
\nNow, by (i) and (ii), we have
\nPQ2<\/sup> = MN2<\/sup> + RS2<\/sup>
\n=|x1<\/sub>-x2<\/sub>|2<\/sup> + |y1<\/sub>-y2<\/sub>|2<\/sup>
\n= (x1<\/sub>-x2<\/sub>)2<\/sup> + (y1<\/sub>-y2<\/sub>)2<\/sup>
\n\u2234 \\( PQ=\\sqrt{{{\\left( {{x}_{1}}-{{x}_{2}} \\right)}^{2}}+{{\\left( {{y}_{1}}-{{y}_{2}} \\right)}^{2}}} \\)
\nFormula (iii) gives the distance between two points whose coordinates are (x1<\/sub>, y1<\/sub>) and (x2<\/sub>, y2<\/sub>). The distance between the points P and Q is also denoted by d(P, Q).
\n\"Distance
\nThus, d(P, Q) = PQ
\n= d(P(x1<\/sub>, y1<\/sub>), Q(x2<\/sub>, y2<\/sub>)) = \\(\\sqrt{{{\\left( {{x}_{1}}-{{x}_{2}} \\right)}^{2}}+{{\\left( {{y}_{1}}-{{y}_{2}} \\right)}^{2}}} \\)
\nIf P and Q lie on X-axis then also formula remains same.
\nHere, M = P and N = O.
\nR = O and S = Q.
\nMN = OP = |x1<\/sub>-0| = |x1<\/sub>| = |x1<\/sub>-y1<\/sub>| (y1<\/sub> = 0)
\nRS = OQ = |0-y2<\/sub>| = |x2<\/sub>-y2<\/sub>| (x2<\/sub> = 0)
\n\u2234 \\(PQ=\\sqrt { { \\left| { { x }_{ 1 } }-{ { x }_{ 2 } } \\right| \u00a0}^{ 2 }+{ \\left| { { y }_{ 1 } }-{ { y }_{ 2 } } \\right| \u00a0}^{ 2 } } =\\sqrt { { { \\left( { { x }_{ 1 } }-{ { x }_{ 2 } } \\right) \u00a0}^{ 2 } }+{ { \\left( { { y }_{ 1 } }-{ { y }_{ 2 } } \\right) \u00a0}^{ 2 } } }\\)
\n\"Distance
\n[Note : P may lie on Y-axis
\nHere x1<\/sub>\u00a0= 0.
\nHere also PS = |y1<\/sub>-y2<\/sub>| (P = R)
\nMN = = |0-x2<\/sub>| = |x2<\/sub>-y2<\/sub>|
\nSimilarly if P lies on X-axis, the formula remains same.]
\nIf PQ is parallel to any axis then x1<\/sub> = x2<\/sub> or y1<\/sub> = y2<\/sub> and formula remains same.<\/p>\n