Multiple choice

If $\alpha ,\beta,\gamma $ are the roots of the equation $x^3 +x+1 = 0$, then the value of $\Pi \left ( \dfrac{1+\alpha }{1-\alpha } \right )$ is equal to.

  1. $-7$
  2. $5$
  3. $3$
  4. $\dfrac13$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For x^3+x+1=0, the product of (1+alpha)/(1-alpha) for roots alpha, beta, gamma is found by evaluating the function at 1 and -1. The result is 1/3.

Keep practicing — related questions