Multiple choice

If $\alpha$, $\beta$ are the roots of the equation $a{ x }^{ 2 }+bx+b=0$, then what is the value of $\sqrt { \dfrac { \alpha }{ \beta } } +\sqrt { \dfrac { \beta }{ \alpha } } +\sqrt { \dfrac { b }{ a } } $?

  1. $-1$
  2. $0$
  3. $1$
  4. $2$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For ax^2 + bx + b = 0, alpha + beta = -b/a and alpha*beta = b/a. The expression is sqrt(alpha/beta) + sqrt(beta/alpha) + sqrt(b/a) = (alpha+beta)/sqrt(alpha*beta) + sqrt(b/a) = (-b/a) / sqrt(b/a) + sqrt(b/a) = -sqrt(b/a) + sqrt(b/a) = 0.

AI explanation

For the equation ax squared plus bx plus b equals 0, Vieta's formulas give the sum of the roots alpha plus beta as negative b over a and the product alpha beta as b over a. By finding a common denominator, the expression simplifies to (alpha plus beta) over the square root of alpha beta plus the square root of b over a. Substituting the sum and product gives (negative b over a) over the square root of b over a plus the square root of b over a, which equals negative 1 plus 1, resulting in 0.