Question

The number of distinct real roots of $x^4 – 4x + 1 = 0$ is :

• A. 4
• B. 2
• C. 1
• D. 0

Answer 1

Answer: (B)

2

Answer 2

$ƒ(x) = x^4 – 4x \+ 1 = 0$

$ƒ′(x) = 4x^3 – 4$

= $4(x – 1) (x^2 \+ 1 + x)$

Hence, the correct option is (B): $2$