Ex 7.4, 1 (Optional) - Chapter 7 Class 10 Coordinate Geometry (Term 1)
Last updated at May 29, 2018 by Teachoo
Last updated at May 29, 2018 by Teachoo
Transcript
Ex 7.4, 1 Determine the ratio in which the line 2x + y 4 = 0 divides the line segment joining the points A(2, 2) and B(3, 7). AB is the line segment joining the Points A (2, 2) and B (3, 7) Let line 2x + y 4 = 0 divide AB in the ratio k : 1 at point P Coordinates of Point P = [( (3) + 1(2))/( + 1),( (7) + 1( 2))/( + 1)] = [( + )/( + ),( )/( + )] . Since point P lies on line 2x + y 4 = 0 Therefore, Putting x = (3 + 2)/( + 1) and y = (7 2)/( +1) in equation of line 2x + y 4 = 0 2 ((3 + 2)/( +1)) + ((7 + 2)/( +1)) 4 = 0 (2(3 + 2) +(7 2) 4( +1))/(( +1)) = 0 6k + 4 + 7k 2 4k 4 = 0 (k + 1) (6 + 7 4)k + 4 2 4 = 0 9k 2 = 0 9k = 2 k = / . Thus, ratio in which P divide AB = k : 1 = 2/9 : 1 = 2 : 9
Ex 7.4 (Optional)
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