IIT JEE , AIEEE Forum - Mathematics , Trignometry

pantpranav

A man moving on a parabolic path finds the angle of elevation of a pole, standing on the focus of the path to be 75⁰. If the directrix of the path is at a distance of 7m from him,find height of the pole.

elastiboysai

eqn of directrix :x+a=0

if he stands at the vertex

a=7

tan 75 = h/7

h=26.12 m

sboosy

directrix = focal distance from vertex = 7(assuming he is at the origin)

tan (75) = h/7

so h = (

3 + 1) /(

3 - 1) *7

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