Question

Qual o resultado da equação biquadrada x⁴-8x²+15=0?

Answer 1

x^4 - 8x^2 + 15 = 0
(x^2)^2 - 8x^2 + 15 = 0
Substituindo x^2 = y
y^2 - 8y + 15 = 0
a=1...b=-8...c=15
formula DELTA
delta = b^2 - 4 a c
delta = (-8)^2 - 4 (1) (15)
delta = 64 - 4 (15)
delta = 64 - 60
delta = 4
formula de BRASKARA
y = - b +,- \/delta /2a
y = - (-8) +,- \/4 / 2(1)
y = 8 +,- 2 / 2
y1 = 8 + 2/2》y1 = 10/2》y1 = 5
y2 = 8 - 2/2》 y2 = 6/2》y2 = 3