Distance of a point from a line
Last updated at August 8, 2026 by Teachoo
Transcript
Ex 9.3, 3 Find the distance of the point (ā1, 1) from the line 12(x + 6) = 5(y ā 2). The distance (d) of a line Ax + By + C = 0 from a point (x1, y1) is d = |š“š„_1 + šµš¦_1 + š¶|/ā(š“^2 + šµ^2 ) The given line is 12(x + 6) = 5(y ā 2) 12x + 12 Ć 6 = 5y ā 5 Ć 2 12x + 72 = 5y ā 10 12x ā 5y + 82 = 0 The above equation is of the form Ax + By + C = 0 where A = 12, B = ā5, and C = 82 Now We have to find distance of a point (ā1, 1) from a line So, x1 = ā1 & y1 = 1 Finding distance d = |š“š„_1 + šµš¦_1 + š¶|/ā(š“^2 + šµ^2 ) Putting values d = | ā 12 ā 5 + 82|/ā((12)2 + ( ā 5)2) d = | ā 12 ā 5 + 82|/ā(144 + 25) d = 65/ā169 d = 65/ā(13 Ć 13) d = 65/13 d = 5 Thus, Required distance = 5 units