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

If the line x1=0 is the directrix of the parabola y2kx+8=0, then values of k are

A
18
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
8
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
4
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
14
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C 4
The given parabola is
y2=kx8=k(x8k)
Shifting the origin to (8/k,0), the parabola becomes Y2=kX where X=x8/k and Y=y.
Directrix of this parabola is X=k4x=k4+8k
and this will coincide with x=1
If 8kk4=132k2=4kk2+4k32=0or (k+8)(k4)=0k=8,4

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
Join BYJU'S Learning Program
CrossIcon