3 Views

Question : The value of $\frac{\sin 25^{\circ}\cos 65^{\circ}+\cos 25^{\circ}\sin 65^{\circ}}{\tan ^{2}70^{\circ}-cosec^{2}20^{\circ}}$ is:

Option 1: –1

Option 2: 0

Option 3: 1

Option 4: 2


Team Careers360 17th Jan, 2024
Answer (1)
Team Careers360 22nd Jan, 2024

Correct Answer: –1


Solution : $\frac{\sin 25^{\circ}\cos 65^{\circ}+\cos 25^{\circ}\sin 65^{\circ}}{\tan ^{2}70^{\circ}-\operatorname{cosec}^{2}20^{\circ}}$
$=\frac{\sin 25^{\circ}\sin 25^{\circ}+\cos 25^{\circ}\cos 25^{\circ}}{\tan ^{2}70^{\circ}-\operatorname{cosec}^{2}20^{\circ}}$
$= \frac{\sin^2 25^{\circ}+\cos^225^{\circ}}{\tan^{2}70^{\circ}-\sec^{2}70^{\circ}}$
$= \frac{1}{-(\sec^ {2}70^{\circ}-\tan^ {2}70^{\circ})}$
$= -1$
Hence, the correct answer is –1.

How to crack SSC CHSL

Candidates can download this e-book to give a boost to thier preparation.

Download Now

Know More About

Related Questions

TOEFL ® Registrations 2024
Apply
Accepted by more than 11,000 universities in over 150 countries worldwide
Manipal Online M.Com Admissions
Apply
Apply for Online M.Com from Manipal University
GRE ® Registrations 2024
Apply
Apply for GRE® Test now & save 10% with ApplyShop Gift Card | World's most used Admission Test for Graduate & Professional Schools
View All Application Forms

Download the Careers360 App on your Android phone

Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile

150M+ Students
30,000+ Colleges
500+ Exams
1500+ E-books