Question

Multimea solutiilor ecuatiei : 6x²-x-1=0 este..

Answer 1

Este o ECUATIE DE GRADUL II:
6x² - x - 1 = 0, a = 6 , b = - 1, c = - 1,
delta = b² - 4ac = ( - 1)² - 4 · 6 · ( - 1)
delta = 1 - 24 · ( - 1)
delta = 1 + 24
delta = 25 ( > 0)
x1 = ( - b - √delta) / 2a = ( 1 - √25) / 2 · 6 = ( 1 - 5) /12 = - 4/12 = - 1/3
x1 = - 1/3
x2 = ( - b + √delta) /2a = ( 1 + √25) / 2 · 6 = ( 1 + 5) / 12 = 6/12 = 1/2
x2 = 1/2
S = [ - 1/3, 1/2}