Most Important Selected Qs for JEE AdvancedMathematicsStraight Lines
Locus of the intersection of the two straight lines passing through (1,0) and (-1,0) respectively and including an angle of 45^ can be a circle with
Options
- ACentre (1,0) and radius 2 .
- BCentre (1, 0) and radius 2.
- CCentre (0,1) and radius 2 .
- DCentre (0,-1) and radius 2 .
Correct answer
D. Centre (0,-1) and radius 2 .
Step-by-step solution
m ₁= k h -1 ; m ₂= k h +1 45^ = | k h -1 - k h +1 1+ k ^2 ~h ^2-1 |= | k ( h +1- h +1) h ^2-1+ k ^2 |h^2+k^2-1= 2 k locus is x^2+y^2 2 y-1=0x^2+(y 1)^2=( 2 )^2 (0,1) or (0,-1) and radius = 2