Question

x⁴-8x²+15=0 Qual a resolução???

Answer 1

x^4-8x^2+15=0
y^2-8y+15=0
delta=b^2-4ac
delta=(-8)^2-4.1.15
delta=64-60
delta=4
y=-b-/+ raiz de delta/2a
y=-(-8)-2/2.1
y=8-2/2
y=6/2
y=3
y=-(-8)+2/2.1
y=8+2/2
y=10/2
y=5
S={3, -3, 5, -5}

Answer 2

x⁴=y²
x²=y
y²-8y+15=0
∆=(-8)²-4*1*15
∆=64-60
∆=4
y=-(-8)±√(4)/2
y=8±2/2
y'=5
y"=3
Logo:
x²=5
x=±√(5)
x²=3
x=±√(3)
S=(-√5,-√3,√3,√5)