Straight Line and Pair of Straight Lines 1 Question 52

52. A straight line L with negative slope passes through the point (8,2) and cuts the positive coordinate axes at points P and Q. Find the absolute minimum value of OP+OQ, as L varies, where O is the origin. (2002,5M)

Show Answer

Solution:

  1. Let L:(y2)=m(x8),m<0

The ponts P and Q are 82m,0 and (0,28m), respectively.

Then, OP+OQ=82m+(28m)=10+2m+(8m)

[using AMGM ]

2m+(8m)216[2m and 8m are positive ]

2m+8m8

102m+8m10+8

OP+OQ18



NCERT Chapter Video Solution

Dual Pane