Question
x+ 3 x is maximum when x is equal to
NDA
Mathematics
Trigonometric Ratios & Identities
2026
NDA 2026 (Phase 1)
NDA Mathematics Question (2026) — Solution
Options
- A. 2
- B. 3
- C. 4
- D. 6
Answer
B. 3
Step-by-step solution
Given expression is f(x) = x + 3 x Multiplying and dividing by 1^2 + ( 3 )^2 = 2 f(x) = 2 ( 1 2 x + 3 2 x ) f(x) = 2 ( 3 x + 3 x ) f(x) = 2 ( x - 3 ) The maximum value of ( x - 3 ) is 1, which occurs when x - 3 = 0 x = 3 Answer: 3
Related: Mathematics — Trigonometric Ratios & Identities · All PYQ Banks