Straight Line Question 265
Question: Two points $ P(a,0) $ and $ Q(-a,0) $ are given, R is a variable point on one side of the line PQ such that $ \angle RPQ-\angle RQP $ is $ 2\alpha $ . Then, the locus of R is
Options:
A) $ x^{2}-y^{2}+2xy\cot 2\alpha -a^{2}=0 $
B) $ x^{2}+y^{2}+2xy\cot 2\alpha -a^{2}=0 $
C) $ x^{2}+y^{2}+2xy\cot 2\alpha +a^{2}=0 $
D) None of the above
Correct Answer: A $ \Rightarrow a^{2}-h^{2}+k^{2}=2hk\cot 2\alpha =0 $ Therefore, the locus of $ R(h,k) $ is $ x^{2}-y^{2}+2xy\cot 2\alpha -a^{2}=0 $ Hence, [a] is the correct answer.Show Answer
Answer:
Solution:
BETA
