নিম্নলিখিত মান নির্ণয় করুন:

cos(36° + A).cos(36° - A) + cos(54° + A).cos(54° - A)

This question was previously asked in
SSC CGL 2023 Tier-I Official Paper (Held On: 14 Jul 2023 Shift 2)
View all SSC CGL Papers >
  1. sin 2A
  2. cos A
  3. sin A
  4. cos 2A

Answer (Detailed Solution Below)

Option 4 : cos 2A
ssc-cgl-crash
Free
PYST 1:SSC CGL 2023 - Quantitative Aptitude(Held On:14 Jul 2023 Shift 1)
1.9 Lakh Users
25 Questions 50 Marks 20 Mins

Detailed Solution

Download Solution PDF

প্রদত্ত:

cos (36° - A) cos (36° + A) + cos (54° - A) cos (54° + A)

অনুসৃত সূত্র:

cos (a - b) = cos a cos b + sin a sin b

sin (90 - a) = cos a

গণনা:

⇒ sin[90 - (36 - A)]sin[90 - (36 + A)] + cos (54° - A) cos (54° + A)

⇒ sin(54º + A)sin(54º - A) + cos (54° - A)cos (54° + A)

⇒ cos(A - B) ব্যবহার করে,

⇒ cos(54 + A - 54 + A) = cos(2A)

সুতরাং, cos (36° - A) cos (36° + A) + cos (54° - A) cos (54° + A) এর মান হল cos(2A) 

Latest SSC CGL Updates

Last updated on Jun 9, 2025

-> The SSC CGL Notification 2025 has been released on 9th June 2025 at ssc.gov.in.

-> The SSC CGL exam registration process is now open and will continue till 4th July 2025, so candidates must fill out the SSC CGL Application Form 2025 before the deadline.

-> 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 SSC CGL exam form.

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

-> The SSC 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.

-> Candidates should also use the SSC CGL previous year papers for a good revision. 

Get Free Access Now
Hot Links: teen patti all app teen patti star teen patti wala game teen patti jodi