Go To Your Study Dashboard

Get Answers to all your Questions

header-bg

The angle of elevation of the top of a tower from a point A due north of it is $\alpha$ and from a point B at a distance of 9 units due west of $\mathrm{A \: is \cos ^{-1}\left(\frac{3}{\sqrt{13}}\right)}$ . If the distance of the point B from the tower is 15 units, then $\cot \alpha$ is equal to :
Option: 1
$\frac{6}{5}$

Option: 2
$\frac{9}{5}$

Option: 3
$\frac{4}{3}$

Option: 4
$\frac{7}{3}$

Answers (1)

best_answer

$\text { Giren } \mathrm{O B=15}$

$\mathrm{\cos B =\frac{3}{\sqrt{13}} }$

$\mathrm{\tan B =\frac{h}{\sqrt{15}} }$
$\mathrm{\frac{2}{\sqrt{3}}=\frac{h}{15} }$
$\mathrm{h=10 }$

$\begin{gathered} \mathrm{O A^2+A B^2=225} \\ \mathrm{O A^2+81=225} \\ \mathrm{O A=12} \end{gathered}$

$\mathrm{\tan 2=\frac{10}{12} }\\ \mathrm{\cot \alpha=\frac{12}{10}=\frac{6}{5}}$

Posted by

seema garhwal

View full answer

JEE Main high-scoring chapters and topics

Study 40% syllabus and score up to 100% marks in JEE

Similar Questions

50 mL of 0.2 M ammonia solution is treated with 25 mL of 0.2 M HCl. If pK_b of ammonia solution is 4.75, the pH of the mixture will be :
Option: 1 3.75
Option: 2 4.75

Trending Articles/News

anam-khan

JEE Main 2025: 11 from Kota coaching centres among 24 students with 100 percentile

anam-khan

Low JEE Main rank? Explore alternative paths for engineering admission

anam-khan

Gender-gap in JEE Main 2025: Female participation remains around 31%, overall pool drops by 7.09%

Latest Question