Question

Determine as raizes da equação x⁴- 5x² + 4= 0

Answer 1

Oi 

x⁴ - 5x² + 4 = 0

y = x²

y² - 5y + 4 = 0

delta
d² = 25 - 16 = 9
d = 3

y1 = (5 + 3)/2 = 8/2 = 4
y2 = (5 - 3)/2 = 2/2 = 1

y = x²

x² = 4 
x1 = -2, x2 = 2

x² = 1
x3 = -1, x4 = 1

S = (-2,-1,1,2)