Question

Реши уравнение x4−17x2+16=0

Answer 1

$x^2=t; t^2-17t+16=0$
 D=289-64=225
  t=(17+15)/2=16 t=(17-15)/2=1
    x^2=16  ==> x=+-4
    x^2=1   ==>x=+-1