Straight Line and Pair of Straight Lines 1 Question 37

37. Line L has intercepts a and b on the coordinate axes. When, the axes are rotated through a given angle, keeping the origin fixed, the same line L has intercepts p and q, then

(1990,2M)

(a) a2+b2=p2+q2

(b) 1a2+1b2=1p2+1q2

(c) a2+p2=b2+q2

(d) 1a2+1p2=1b2+1q2

Show Answer

Solution:

  1. Since, the origin remains the same. So, length of the perpendicular from the origin on the line in its position xa+yb=1 and xp+yq=1 are equal. Therefore,

11a2+1b2=11p2+1q21a2+1b2=1p2+1q2



NCERT Chapter Video Solution

Dual Pane