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What is the value of cos 18° - sin 18° ? 

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Airforce Group X MBT 15-Jul-2021 Shift 3
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  1. √2 sin27° 
  2. sin27° 
  3. √2 cos27° 
  4. ​cos27° 

Answer (Detailed Solution Below)

Option 1 : √2 sin27° 
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Detailed Solution

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Concept:

cos (90 - x) = sin x

sin A - sin B = 2cossin 

cos 45° = 

 

Calculation:

Given,

cos18° - sin18°

= cos (90° - 72°) - sin 18°

= sin 72° - sin 18°

= 2 cos × sin 

= 2 cos 45° sin 27°

= 2× × sin 27°

= √2 sin 27° 

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Last updated on Jun 30, 2025

->Indian Airforce Agniveer (02/2026) Notification has been released. Interested candidates can apply between 11th July to 31st July 2025.

->The Examination will be held 25th September 2025 onwards.

-> Earlier, Indian Airforce Agniveer Group X 2025 Last date had been extended.

-> Candidates applied online from 7th to 2nd February 2025.

-> The online examination was conducted from 22nd March 2025 onwards.

-> The selection of the candidates will depend on three stages which are Phase 1 (Online Written Test), Phase 2 ( DV, Physical Fitness Test, Adaptability Test), and Phase 3 (Medical Examination).

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