Multiple choice

For what value of n does the equation x2 + 2nx + n + 6 = 0 have equal roots?

  1. 0

  2. 3

  3. 4

  4. 6

  5. 8
Reveal answer Fill a bubble to check yourself
B Correct answer
AI explanation

For a quadratic equation to have equal roots, its discriminant must equal zero. Using the discriminant formula b^2 - 4ac = 0 with a = 1, b = 2n, and c = n + 6, we write (2n)^2 - 4(1)(n + 6) = 0. This simplifies to 4n^2 - 4n - 24 = 0, or n^2 - n - 6 = 0, which factors as (n - 3)(n + 2) = 0. Since the question asks for a positive value, the result is 3.

Keep practicing — related questions