Question
Consider the following for the two (02) items that follow: Let 2 + = 2, where 0 What is 2 2 + 2 equal to?
NDA
Mathematics
Trigonometric Ratios & Identities
2025
NDA 2025 (Phase 1)
NDA Mathematics Question (2025) — Solution
Options
- A. 11 10
- B. 11 5
- C. 12 5
- D. 13 5
Answer
B. 11 5
Step-by-step solution
Given 2 + = 2 = 2(1 - ) Squaring both sides: ^2 = 4(1 - )^2 1 - ^2 = 4(1 - 2 + ^2 ) 5 ^2 - 8 + 3 = 0 (5 - 3)( - 1) = 0 Since 0 This gives = 1 - ( 3 5 )^2 = 4 5 . Now, 2 = 2 = 2 ( 3 5 ) ( 4 5 ) = 24 25 2 = ^2 - ^2 = ( 4 5 )^2 - ( 3 5 )^2 = 7 25 Therefore, 2 2 + 2 = 2 ( 24 25 ) + 7 25 = 48 + 7 25 = 55 25 = 11 5 . Answer: 11 5
Related: Mathematics — Trigonometric Ratios & Identities · All PYQ Banks