Question:

By Newton-Raphson method, the positive root of \(x^4 - x - 10 = 0\) is:

Show Hint

Newton-Raphson converges quadratically; choose initial guess close to the root.
Updated On: Apr 16, 2026
  • 1.871
  • 1.868
  • 1.856
  • None of these
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Concept: Newton-Raphson iteration: \(x_{n+1} = x_n - \frac{f(x_n)}{f'(x_n)}\), where \(f(x) = x^4 - x - 10\) and \(f'(x) = 4x^3 - 1\).

Step 1:
Choose initial guess. \(x_0 = 2\) (since \(2^4 - 2 - 10 = 16 - 12 = 4>0\), and \(1.8^4 \approx 10.5\)).

Step 2:
First iteration. \[ x_1 = 2 - \frac{16 - 2 - 10}{32 - 1} = 2 - \frac{4}{31} \approx 2 - 0.129 = 1.871 \]

Step 3:
Second iteration (for verification). \[ f(1.871) \approx (1.871)^4 - 1.871 - 10 \approx 12.25 - 11.871 \approx 0.379 \] \[ f'(1.871) = 4(1.871)^3 - 1 \approx 4(6.55) - 1 \approx 26.2 - 1 = 25.2 \] \[ x_2 = 1.871 - \frac{0.379}{25.2} \approx 1.871 - 0.015 = 1.856 \]
Was this answer helpful?
0
0