Algebra Questions

Multiple choice
  1. $3$
  2. $-3$
  3. $6$
  4. $-6$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Given x^2 - 6x - 2 = 0, we have alpha^2 = 6alpha + 2 and beta^2 = 6beta + 2. Multiplying by alpha^(n-2) and beta^(n-2) respectively leads to the recurrence relation a_n = 6a_(n-1) + 2a_(n-2). Rearranging gives (a_n - 2a_(n-2)) / a_(n-1) = 6. For n=10, (a_10 - 2a_8) / a_9 = 6. Dividing by 2 gives 3.

Multiple choice
  1. $x=-2, 4$
  2. $x=2,-4$
  3. $x=2,6$
  4. $x=-2,-4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The vertex of the parabola is at x = -b/(2a) = 1. Since f(-2) = 0 and the axis of symmetry is x = 1, the other root must be equidistant from 1. The distance from -2 to 1 is 3, so the other root is 1 + 3 = 4.