wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Let 2x2+y23xy=0 be the equation of a pair of tangents drawn from the origin O to a circle of radius 3 units with centre in the first quadrant. If A is one of the points of contact, then the length of OA is

A
3+10 units
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
9(1+10) units
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
3(3+10) units
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
9+10 units
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 3(3+10) units
y23xy+2x2=0
Let θ be the angle between the two lines. Then,
tanθ=2(9/4)21+2=13
but from angle between the formulae
tanθ=2LrL2r2,
Hence, 13=6LL29
L218L9=0
L=9±90
As L can't be negative,
L=9+90
L=3(3+10)
OA=L=3(3+10) units

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Tangent to a Circle
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon