Question
If ^ -1 k + ^ -1 1 2 = 4 , then what is the value of k?
NDA
Mathematics
Inverse Trigonometric Functions
2025
NDA 2025 (Phase 1)
NDA Mathematics Question (2025) — Solution
Options
- A. 1
- B. 1 2
- C. 1 3
- D. 1 4
Answer
C. 1 3
Step-by-step solution
Given ^ -1 k + ^ -1 1 2 = 4 Using the formula ^ -1 x + ^ -1 y = ^ -1 ( x+y 1-xy ), we get: ^ -1 ( k + 1 2 1 - k 2 ) = 4 2k + 1 2 - k = ( 4 ) 2k + 1 2 - k = 1 2k + 1 = 2 - k 3k = 1 k = 1 3 Answer: 1 3
Related: Mathematics — Inverse Trigonometric Functions · All PYQ Banks