Question:medium

Given below are pair of functions \(f(x)\) and \(g(x)\). Which pair is not linearly independent?

Show Hint

For function pairs, look for standard trigonometric expansions like \(\sin(3\theta)\) or \(\cos(3\theta)\).
If \(g(x) = c \cdot f(x)\) holds for all \(x\), the Wronskian is zero, meaning they are not linearly independent.
Updated On: Jun 23, 2026
  • \(f(x) = \cos x + \sin x\), \(g(x) = -6\cos\frac{x}{3} - 8\cos^3\frac{x}{3}\)
  • \(f(x) = -\cos x + \sin x\), \(g(x) = \cos x\)
  • \(f(x) = \cos x\), \(g(x) = \cos^3 x - \sin^3 x\)
  • \(f(x) = \sin x\), \(g(x) = 6\sin\frac{x}{3} - 8\sin^3\frac{x}{3}\)
Show Solution

The Correct Option is D

Solution and Explanation

Was this answer helpful?
0