Question

Resolva a equação:
${x}^{4} + 36 - {20x}^{2} = 0$
​

Answer 1

sendo:

x⁴ - 20x² + 36 = 0

y = x²

y² - 20y + 36 = 0

delta:

d = 400 . 144 = 256 = 16²

y1 = (20 + 16)/2 = 18

y2 = (20 - 16)/2 = 2

as raizes:

x1 = √18 = 3√2

x2 = -√18 = -3√2

x3 = √2

x4 = -√2