Browse by Stream
QnA
Home
QnA
Go To Your Study Dashboard

Get Answers to all your Questions

header-bg qa
  • Home
  • Engineering
  • Slope of common tangent to parabolas   and <img alt="\mathrm{x^2=8 y}

Slope of common tangent to parabolas  \mathrm{y^2=4 x} and \mathrm{x^2=8 y} is

Option: 1

\mathrm{-\left(\frac{1}{2}\right)^{1 / 3}}


Option: 2

\mathrm{\frac{1}{\sqrt{2}}}


Option: 3

\mathrm{\frac{1}{\sqrt{3}}}


Option: 4

 none of these 

 


Answers (1)

best_answer

Any tangent to \mathrm{y^2=4 x} will be to the form \mathrm{y=m x+\frac{1}{m}} . If this is a tangent to \mathrm{x^2=8 y}, then roots of \mathrm{x^2-8 m x-\frac{8}{m}=0}
 must be real and equal so \mathrm{64 m^2+\frac{32}{m}=0 \Rightarrow m=-\left(\frac{1}{2}\right)^{1 / 3} .}.

Hence answer is (a).

 

Posted by

shivangi.shekhar

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