Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • The chord of contact of tangents drawn from any point on the circle <img alt="x^{2}+ y^{2} = a^{2}" src="https://entrancecorner.oncodecogs.com/gif.latex?x%5E%7B2%7D&p

The chord of contact of tangents drawn from any point on the circle x^{2}+ y^{2} = a^{2}  to the circle x^{2}+ y^{2} = b^{2}touches x^{2}+ y^{2} = c^{2}. Then a, b, c are in:

 

Option: 1

A.P


Option: 2

G.P


Option: 3

H.P


Option: 4

A.G.P


Answers (1)

best_answer

Let (x1, y1) be any point on the circle  x^{2} + y^{2} = a^{2}
\Rightarrow x_1^2+y_1^2=a^2

chord of contact of \left(x_1, y_1\right) with respect to x^2+y^2=b^2 is  x_1+y y_1=b^2 This touches  x^2+y^2=c^2
\begin{aligned} & \frac{b^2}{\sqrt{x_1^2+y_1^2}}=c \\ \Rightarrow & \frac{b^2}{a}=c \\ \Rightarrow & b^2=a c \end{aligned}

Hence a, b, c are in G.P.

 

Posted by

Devendra Khairwa

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

Latest Question