Matematika

Pertanyaan

jika akar persamaan kuadrat 3xkuadrat +6x+12=0 adalah αdan β, maka nilai 1perαkuadrat + 1 per βkuadrat =....

2 Jawaban

  • • a+b = -6/3
    a+b = -2

    • ab = 12/3
    ab = 4

    • 1/a^2 + 1/b^2
    = (a^2 + b^2) / a^2 . b^2
    = [(a+b)^2 - 2ab] / (ab)^2
    = [(-2)^2 - 2(4)] / (4)^2
    = [4-8] / 16
    = -4/16
    = -1/4
  • Solusi
    3x² + 6x + 12 = 0
    a = 3, b = 6 dan c = 12

    α + β = -6/3 = -2
    αβ = 12/3 = 4
    α² + β² = (α + β) - 2αβ = (-2)² - 2(4) = -4

    Dengan demikian:
    = 1/α² + 1/β²
    = (α² + β²)/(αβ)²
    = (-4)/(4)²
    = -4/16
    = -1/4

Pertanyaan Lainnya