Circle-And-System-Of-Circles Question 376
Question: The condition that the line $ x\cos \alpha +y\sin \alpha =p $ may touch the circle $ x^{2}+y^{2}=a^{2} $ is
[AMU 1999]
Options:
A) 20
B) 30
C) 40
D) 50
Show Answer
Answer:
Correct Answer: C
Solution:
Length of tangent = $ \sqrt{3^{2}+{{(-4)}^{2}}-4,(3),-6,(-4)+3} $ $ =\sqrt{40} $
$ \therefore $ Square of length of tangent $ =40 $ .
BETA
