Find the value of \({\cos^215^{\circ} - \sin^215^{\circ}} \over{\cos^2145^{\circ} + \sin^2145^{\circ}}\)

This question was previously asked in
SSC CGL 2023 Tier-I Official Paper (Held On: 26 Jul 2023 Shift 3)
View all SSC CGL Papers >
  1. \(1 \over \sqrt3\)
  2. \(1 \over 1 - \sqrt3\)
  3. \(\sqrt3 \over 2\)
  4. \(2 \over \sqrt3\)

Answer (Detailed Solution Below)

Option 3 : \(\sqrt3 \over 2\)
super-pass-live
Free
SSC CGL Tier 1 2025 Full Test - 01
3.3 Lakh Users
100 Questions 200 Marks 60 Mins

Detailed Solution

Download Solution PDF

Concept used:

Sin2θ + Cos2θ = 1

Cos 2θ - Sin2θ = Cos2θ

Calculation:

\({\cos^215^{\circ} - \sin^215^{\circ}} \over{\cos^2145^{\circ} + \sin^2145^{\circ}}\)

⇒ Cos (2 ×15°)

⇒ Cos 30° = \(\sqrt3 \over 2\)

∴ The correct option is 3

Latest SSC CGL Updates

Last updated on Jul 8, 2025

-> The SSC CGL Notification 2025 for the Combined Graduate Level Examination has been officially released on the SSC's new portal – www.ssc.gov.in.

-> This year, the Staff Selection Commission (SSC) has announced approximately 14,582 vacancies for various Group B and C posts across government departments.

-> The SSC CGL Tier 1 exam is scheduled to take place from 13th to 30th August 2025.

->  Aspirants should visit ssc.gov.in 2025 regularly for updates and ensure timely submission of the CGL exam form.

-> Candidates can refer to the CGL syllabus for a better understanding of the exam structure and pattern.

-> The CGL Eligibility is a bachelor’s degree in any discipline.

-> Candidates selected through the SSC CGL exam will receive an attractive salary. Learn more about the SSC CGL Salary Structure.

-> Attempt SSC CGL Free English Mock Test and SSC CGL Current Affairs Mock Test.

-> The CSIR NET Exam Schedule 2025 has been released on its official website.

Get Free Access Now
Hot Links: teen patti master apk best teen patti chart teen patti master new version