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

A vertical pole consists of two parts, the lower part being one third of the whole. At a point in the horizontal plane through the base of the pole and distance 20m from it, the upper part of the pole subtends an angle whose tangent is 1/2. The possible heights of the pole are -

A
20m and 203m
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
20m and 60m
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
16m and 48m
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
None of these
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B 20m and 60m
Now tanβ=h60, tan(α+β)=h20
tan(α+β)=tanαtanβ1tanαtanβ = h20
=> 12+h601h120 = h20
60+2h120h=h20

h280h+1200=0

By solving this we get h = 20m or 60m.



981048_1078221_ans_3198eebc5e9d48f9ad53baa35f5026c9.PNG

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Tango With Straight Lines !!
MATHEMATICS
Watch in App
Join BYJU'S Learning Program
CrossIcon