Flag Engineering Entrance Exams> parabola straight lines...
question mark

1. the angle between the tangents drawn from the point (1,4)to the parabola y=4x is2. In what ratio is the line y-x+2=0 divides the line joining the point (3,-1) & (8,9)

rajan thakare , 13 Years ago
Grade
anser 1 Answers
jitender lakhanpal

Last Activity: 13 Years ago

Dear  rajan,

eqution of pair of tangent   SS1 = T2

 12(Y2 - 4X)  =(4Y-2X-2)2

WE GET   4X2 +4Y2 -16XY - 40X-16Y+4 = 0

TANß = 2√H2-AB/A+B       ABOVE EQUTION H = -8 ,A = 4,B=4

AND PUTTING THE VALUES WE GET TANß = √3  ß = 60 AND 300

QUES 2     

   LET Xm , Ym  BE THE POINTS THAT LIES ON THE LINE and divides the line joining (3, -1) (8,9) in ratio m,n

 

Xm = (3m+8n)/(m+n)     Ym = (-m+9n)/(m+n)  AS THE POINTS LIE ON THE LINE SO 

Ym-Xm+2=0

  (3m+8n)/(m+n) -(-m+9n)/(m+n) = -2

taking n common 

(3(m/n) + 8) /((m/n)+1) -(-(m/n) + 9) /((m/n)+1) = -2 

take m/n as p 

solving we get 

  p = 1/6  is the answer 

We are all IITians and here to help you in your IIT JEE preparation.

Now you can win exciting gifts by answering the questions on Discussion Forum. So help discuss any query on askiitians forum and become an Elite Expert League askiitian.

Now you score 5+15 POINTS by uploading your Pic and Downloading the Askiitians Toolbar: Click here to download the toolbar..  

jitender 

askiitians expert

Provide a better Answer & Earn Cool Goodies

Enter text here...
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments


Ask a Doubt

Get your questions answered by the expert for free

Enter text here...

question mark
consider the figure of a single riveted lap joint as follows
Engineering Entrance Exams
0 Answer Available

Last Activity: 2 Year ago(s)

question mark
Hello, Can we learn and prepare for MHT-CET online ?
Engineering Entrance Exams
0 Answer Available

Last Activity: 3 Year ago(s)