Question

Resolva a equação biquadrada .
x^4+6x^2-27=0

Answer 1

biquadrada                                                            como x²=y
x²=y         y²+6y-27=0                                                       x² =3

                   Δ=36 +108=144     √Δ=12                               x = + ou - √3

                       y=(-6+12)/2 =6/2 = 3                                  S= {-√3,√3}

                        y=(-6-12)/2 = -18/2 = -9  não serve