Question

como resolvo essa equação Biquadrada 4x^4-7x^2+4=0

Answer 1

$4x^4-7x^2+4=0\\\\t=x^2\\\\4t^2-7t+4=0\\\\\Delta=49-4.4.4=-15\\\\t_1= \frac{7+i \sqrt{15}}{2.4} \\\\t_1=\frac{7+i \sqrt{15}}{8}\\\\t_2=\frac{7-i \sqrt{15}}{8}\\\\ \sqrt{t_n}=x\\\\ \\\\x_1=\sqrt{\frac{7-i \sqrt{15}}{8}}\\\\\boxed{x_1=\frac{ \sqrt{7-i \sqrt{15}}}{2 \sqrt{2}}}\\\\\boxed{x_2=\frac{ \sqrt{7+i \sqrt{15}}}{2 \sqrt{2}}}$